Papers by Elizabeth S Muxfeldt
Journal of Hypertension, Jun 1, 2008
Nocturnal blood pressure (BP) reduction and ambulatory pulse pressure (PP) are well known prognos... more Nocturnal blood pressure (BP) reduction and ambulatory pulse pressure (PP) are well known prognostic markers obtained from ambulatory BP monitoring (ABPM). The aim of this study is to investigate which one of these ABPM parameters is related to high cardiovascular risk profile in resistant hypertension, based on their associations with target organ damage (TOD). Clinical-demographic, laboratory and ABPM variables were recorded in a cross-sectional study involving 907 resistant hypertensive patients. Nocturnal systolic BP reduction and 24-h PP were assessed both as continuous and dichotomized variables (PP at the upper tertile value: 63 mmHg). Statistical analyses included bivariate tests and multivariate logistic regression with each TOD as the dependent variable. Patients with the nondipping pattern and high 24-h PP shared some characteristics: they were older, had higher prevalence of cerebrovascular disease and nephropathy, higher office and 24-h BP levels, increased serum creatinine and microalbuminuria, and higher left ventricular mass index than their counterparts. Additionally, patients with high PP had a greater prevalence of diabetes and other TOD. In multivariate logistic regression, high PP was independently associated with all TODs even after adjustment for sex, age, BMI, cardiovascular risk factors, 24-h mean arterial pressure and antihypertensive treatment, whereas nondipping pattern was only associated with hypertensive nephropathy. Furthermore, PP was more strongly associated with the number of TOD than the nocturnal systolic blood pressure (SBP) fall. In a large group of resistant hypertensive patients, an increased 24-h PP shows a closer correlation with high cardiovascular risk profile than the nocturnal BP reduction.
Journal of Hypertension, 2008
Nocturnal blood pressure (BP) reduction and ambulatory pulse pressure (PP) are well known prognos... more Nocturnal blood pressure (BP) reduction and ambulatory pulse pressure (PP) are well known prognostic markers obtained from ambulatory BP monitoring (ABPM). The aim of this study is to investigate which one of these ABPM parameters is related to high cardiovascular risk profile in resistant hypertension, based on their associations with target organ damage (TOD). Clinical-demographic, laboratory and ABPM variables were recorded in a cross-sectional study involving 907 resistant hypertensive patients. Nocturnal systolic BP reduction and 24-h PP were assessed both as continuous and dichotomized variables (PP at the upper tertile value: 63 mmHg). Statistical analyses included bivariate tests and multivariate logistic regression with each TOD as the dependent variable. Patients with the nondipping pattern and high 24-h PP shared some characteristics: they were older, had higher prevalence of cerebrovascular disease and nephropathy, higher office and 24-h BP levels, increased serum creatinine and microalbuminuria, and higher left ventricular mass index than their counterparts. Additionally, patients with high PP had a greater prevalence of diabetes and other TOD. In multivariate logistic regression, high PP was independently associated with all TODs even after adjustment for sex, age, BMI, cardiovascular risk factors, 24-h mean arterial pressure and antihypertensive treatment, whereas nondipping pattern was only associated with hypertensive nephropathy. Furthermore, PP was more strongly associated with the number of TOD than the nocturnal systolic blood pressure (SBP) fall. In a large group of resistant hypertensive patients, an increased 24-h PP shows a closer correlation with high cardiovascular risk profile than the nocturnal BP reduction.
Hypertension Research, 2013
Resistant hypertension is defined as an uncontrolled office blood pressure (BP) despite the use o... more Resistant hypertension is defined as an uncontrolled office blood pressure (BP) despite the use of at least three antihypertensive drugs, in adequate doses and combinations, preferentially including one diuretic. It is a clinical diagnosis based on office BP measurements. Ambulatory BP monitoring (ABPM) is the cornerstone in the management of patients with resistant hypertension, as it is mandatory for diagnosis, treatment, follow-up and prognosis. In relation to diagnosis, ABPM measurements have classified patients with resistant hypertension into four subgroups: true, white-coat, controlled and masked resistant hypertension. This classification largely defines the therapeutic approach and the follow-up for each group. In this way, the target of antihypertensive treatment is ambulatory BP control and not office BP control. Chronotherapy based on ABPM values might frequently lead to a more rational treatment regimen. In relation to prognosis, uncontrolled ambulatory BP levels at baseline identify a subgroup of patients with a very high cardiovascular risk profile and a significantly worse prognosis. ABPM parameters can provide a better cardiovascular risk stratification than other traditional risk factors and office BPs.
Pharmacogenomics, 2014
Hydralazine, a vasodilator used in resistant hypertension (RH) treatment is metabolized by an ace... more Hydralazine, a vasodilator used in resistant hypertension (RH) treatment is metabolized by an acetylation reaction mediated by N-acetyltransferase 2, the activity of which depends on NAT2 polymorphisms. Our aim was to evaluate whether different acetylation phenotypes influenced the antihypertensive effect of hydralazine in patients with RH. DNA samples from 169 RH patients using hydralazine were genotyped by sequencing the NAT2 coding region, and acetylation phenotypes were defined. Sixty-five patients (38.5%) were intermediate, 60 (35.5%) slow and 21 (12.4%) fast acetylators. Twenty-three (13.6%) patients were indeterminate. Upon association analysis, only slow acetylators had significant blood pressure reductions after hydralazine use, with mean 24-h systolic and diastolic blood pressure reductions of 9.2 and 5.5 mmHg. Four patients presented hydralazine adverse effects resulting in drug withdrawal, three of them were slow acetylators. The slow acetylation phenotype, determined by polymorphisms within NAT2, influenced both the antihypertensive and adverse effects of hydralazine in RH.
Journal of Hypertension, Nov 1, 2003
To assess the effect of orlistat plus diet compared with diet alone in promoting weight loss and ... more To assess the effect of orlistat plus diet compared with diet alone in promoting weight loss and blood pressure reduction in hypertensive, overweight/obese patients. A pragmatic randomized, controlled trial. Hypertension clinic of a university hospital. Hypertensive patients aged 18-75 years with a body mass index greater than 25 kg/m(2). Orlistat 360 mg/day combined with a hypocaloric diet (treatment group), or a calorie-restricted diet alone (control group). Primary outcomes were reductions in weight and blood pressure. Secondary outcomes were decreases in lipid and glucose concentrations. A subgroup analysis of the main outcomes among diabetic and non-diabetic patients was also performed. A total of 204 patients were included in the intention-to-treat analysis. After 12 weeks the orlistat group lost, on average, 3.7 kg and the control group lost 2.0 kg in weight (P < 0.001). Systolic (SBP) and diastolic (DBP) blood pressures decreased by 15.3 and 11.4 mmHg, respectively, in the group given orlistat plus a hypocaloric diet and by 11.6 and 5.2 mmHg, respectively, in the control group given the calorie-restricted diet alone (P = 0.25 and P = 0.0004, respectively). Fasting glucose (0.82 and 0.17 mmol/l, P = 0.01) and total cholesterol (0.85 and 0.56 mmol/l, P = 0.05) were reduced to a greater extent with orlistat than with diet alone. The mean reduction in triglycerides with orlistat plus the hypocaloric diet was 0.75 mmol/l and that in the control group was 0.30 mmol/l (P = 0.28); the increases in high-density lipoprotein cholesterol were 0.05 and 0.00 mmol/l, respectively, in the two groups (P = 0.17). Treatment improved blood pressure and glucose control in the individuals with diabetes, but not in those without diabetes. In both groups there was a reduction in weight, blood pressure and metabolic parameters. The orlistat group performed better in reducing weight, DBP, glucose and cholesterol. Results show that even a small reduction in weight helps to control blood pressure and glucose. The cost-benefit of the use of orlistat should be evaluated for hypertensive obese patients.
Journal of Hypertension, 2015
Endothelial function by flow-mediated (FMD) and nitroglycerin-mediated vasodilations (NMD) was sc... more Endothelial function by flow-mediated (FMD) and nitroglycerin-mediated vasodilations (NMD) was scarcely investigated in resistant hypertension. We aimed to assess the independent correlates of FMD and NMD in resistant hypertensive patients, particularly their associations with ambulatory blood pressures (BP) and nocturnal BP fall patterns. In a cross-sectional study, 280 resistant hypertensive patients performed 24-h ambulatory BP monitoring, carotid-femoral pulse wave velocity, polysomnography, and brachial artery FMD and NMD by high-resolution ultrasonography. Independent correlates of FMD, NMD, and brachial artery diameter (BAD) were assessed by multiple linear and logistic regressions. Median (interquartile range) FMD was 0.75% (-0.6 to +4.4%) and NMD was 11.8% (7.1-18.4%). Baseline BAD and diabetes were independently associated with both FMD and NMD. Older age and prior cardiovascular diseases were associated with altered FMD, whereas higher night-time SBP and lower nocturnal SBP fall were associated with impaired NMD. Moreover, there was a significant gradient of impaired NMD according to blunted nocturnal BP decline patterns. BAD was independently associated with age, sex, BMI, albuminuria, and nocturnal SBP fall. Further adjustments to blood flow velocity, aortic stiffness, plasma aldosterone concentration, and sleep apnea did not change these relationships. NMD, but not FMD, is independently associated with unfavorable night-time BP levels and nondipping patterns, and may be a better cardiovascular risk marker in patients with resistant hypertension. BAD also may provide additional prognostic information.
Journal of Hypertension, 2015
Correlates of serial aortic stiffness changes were scarcely evaluated. We aimed to evaluate them ... more Correlates of serial aortic stiffness changes were scarcely evaluated. We aimed to evaluate them in patients with resistant hypertension, with particular attention to the importance of changes in clinic and ambulatory blood pressures (BP). In a prospective study, two carotid-femoral pulse wave velocity (cf-PWV) measurements (three measures in each occasion) were performed with the Complior equipment in 442 resistant hypertensive patients over a mean follow-up of 4.6 years. Multivariable regressions assessed the independent correlates of changes in cf-PWV. All analyses were further adjusted for baseline cf-PWV and BP values, and for the time interval between measurements. Carotid-femoral PWV had a median increase of 0.11 m/s per year (1.1% per year). Overall, 224 patients (51%) had an increase or persisted with high cf-PWV, whereas 218 (49%) reduced or persisted with low values. On multivariable regressions, both changes in clinic SBP (partial correlation 0.34, P < 0.001) and in 24-h SBP (partial correlation 0.40, P < 0.001) were correlates of changes in cf-PWV. This means that the white-coat effect, defined as the difference between clinic and daytime BPs, affected cf-PWV changes (partial correlation 0.19, P < 0.001). The other independent correlates of aortic stiffness progression were older age, presence of diabetes, higher waist circumference and worse renal function. The exaggerated white-coat effect, by acutely increasing clinic BPs during cf-PWV examination, may partially obscure the beneficial effects of reducing ambulatory BP levels on aortic stiffness attenuation. Arterial stiffness measurements under ambulatory conditions may be needed to correctly assess aortic stiffness changes in resistant hypertensive patients.
American journal of hypertension, 2013
The prognostic significance of heart rate (HR) and its relationship with beta-blocker use are con... more The prognostic significance of heart rate (HR) and its relationship with beta-blocker use are controversial and have never been evaluated in resistant hypertension. In a prospective study, 528 patients with resistant hypertension had HR measured on clinical examination, electrocardiography (ECG), and during ambulatory blood pressure monitoring. Primary endpoints were a composite of fatal and nonfatal cardiovascular events, all-cause and cardiovascular mortality. Multivariable Cox regression was used to assess the associations between slow HR (< 60 bpm or < 55 bpm for nighttime HR) and fast HR (> 75 bpm or > 70 bpm for nighttime HR) and the occurrence of endpoints in relation to the reference middle HR (60-75 bpm) subgroup. After a median follow-up of 4.8 years, 62 patients died, 44 from cardiovascular causes; and 94 cardiovascular events occurred. Fast and slow HRs were mainly predictors of mortality, and ambulatory HRs were more significant risk markers than clinic or E...
American journal of hypertension, 2015
Ambulatory blood pressure (BP) monitoring (ABPM) is a cornerstone in resistant hypertension (RHT)... more Ambulatory blood pressure (BP) monitoring (ABPM) is a cornerstone in resistant hypertension (RHT) management. However, it has higher cost and lower patients' acceptance than home BP monitoring (HBPM). Our objective was to evaluate HBPM usefulness in the management of patients with RHT. A total of 240 patients were submitted to 24-hour ABPM and 5-day HBPM (triplicate morning and evening measurements). Patients with uncontrolled office BP (≥140/90mm Hg) were classified as true RHT (daytime or home BP ≥135/85mm Hg) or white-coat RHT (daytime or home BP <135/85mm Hg), and patients with controlled office BP were classified as masked RHT (daytime or home BP ≥135/85mm Hg) or controlled RHT (daytime or home BP <135/85mm Hg). Sensitivity, specificity, predictive values, and likelihood ratios for HBPM were calculated. Agreement between the procedures was evaluated using kappa coefficients and the Bland-Altman method. Mean office BP was 157±26/84±16mm Hg, mean daytime BP was 134±18/7...
Hypertension, Jan 19, 2015
The effect of continuous positive airway pressure (CPAP) on blood pressures (BPs) in patients wit... more The effect of continuous positive airway pressure (CPAP) on blood pressures (BPs) in patients with resistant hypertension and obstructive sleep apnea is not established. We aimed to evaluate it in a randomized controlled clinical trial, with blinded assessment of outcomes. Four hundred thirty-four resistant hypertensive patients were screened and 117 patients with moderate/severe obstructive sleep apnea, defined by an apnea-hypopnea index ≥15 per hour, were randomized to 6-month CPAP treatment (57 patients) or no therapy (60 patients), while maintaining antihypertensive treatment. Clinic and 24-hour ambulatory BPs were obtained before and after 6-month treatment. Primary outcomes were changes in clinic and ambulatory BPs and in nocturnal BP fall patterns. Intention-to-treat and per-protocol (limited to those with uncontrolled ambulatory BPs) analyses were performed. Patients had mean (SD) 24-hour BP of 129(16)/75(12) mm Hg, and 59% had uncontrolled ambulatory BPs. Mean apnea-hypopne...
American Journal of Hypertension, 2008
Two electrocardiographic markers of ventricular repolarization abnormalities have been recently p... more Two electrocardiographic markers of ventricular repolarization abnormalities have been recently proposed: spatial T-wave axis deviation and T(peak)-T(end)-interval duration. The aim of this study was to evaluate these markers in patients with resistant hypertension, particularly their relationships with left ventricular mass (LVM) and geometric patterns, in comparison with the more traditional marker, the QTc interval. In a cross-sectional study, 810 resistant hypertensive patients were evaluated. Clinical, laboratory, electrocardiographic, 24-h blood pressures and echocardiographic variables were obtained. Maximum T(peak)-T(end)-interval duration (Tpe(max)) was considered prolonged if it was beyond the upper quartile value (120 ms), and the spatial T-wave axis on the frontal plane was considered abnormally deviated if &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;105 degrees or &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 15 degrees . Statistical analysis involved bivariate tests, multivariate logistic regression and analysis of covariance. Tpe(max)-interval prolongation, like QTc-interval prolongation, was found to be associated with body mass index, 24-h systolic blood pressure (SBP), indexed LVM, serum potassium, and heart rate. Abnormal T-axis deviation was associated with male gender, presence of coronary heart disease, serum creatinine, 24-h SBP, LVM, and serum potassium. All three repolarization parameters were shown to be associated with increased LVM, after adjustment for possible confounders. However, when included together into the same model, only abnormal T-axis and QTc-interval prolongation remained independently associated with LVM. All three parameters were also increased in patients with concentric hypertrophy geometric pattern. Both the recently proposed repolarization parameters are associated with increased LVM and hypertrophy in patients with resistant hypertension, but only abnormal T-wave axis deviation appears to have distinct and additive relationships to the more classic marker, the QTc interval. Their prognostic values should be addressed in prospective studies .
American Journal of Hypertension, 2012
Diagnostic cut-off values for ambulatory blood pressure monitoring (ABPM) in diabetic patients ar... more Diagnostic cut-off values for ambulatory blood pressure monitoring (ABPM) in diabetic patients are not established. The aim was to investigate associations between office and ambulatory blood pressures (BPs) and diabetic chronic complications and to establish optimal threshold ambulatory BP values regarding the likehood of having microvascular complications in type 2 diabetes. In a cross-sectional design, clinical, laboratory, and 24-h ABPM data were obtained in 550 type 2 diabetic patients. Multivariate logistic regression assessed the associations between office and ambulatory BPs and diabetic micro and macrovascular complications. Optimal threshold values for ambulatory BPs (daytime, night-time, and 24 h) were established by examining the best combination of systolic (SBP) and diastolic BP (DBP) that maximized the odds ratios (ORs) of having each microvascular complication. After multivariate adjustment for all potential confounders, ambulatory SBPs were more strongly associated with diabetic complications than office BPs, except for retinopathy and nephropathy, in which both were equivalent. In general, night-time BPs were stronger correlates than daytime BPs. The optimal threshold ambulatory BP values were 125/75 mm Hg for daytime, 110/65 mm Hg for night-time, and 120/75 mm Hg for the 24-h period, with odds ranging from 1.7- to 2.3-fold of having each microvascular complication. Except for retinopathy and advanced nephropathy, ambulatory BPs are better correlates of chronic complications than office BPs in type 2 diabetes. The association of microvascular complications with lower ambulatory BP levels than those reported as normal for nondiabetic patients may indicate that lower cut-off values for ambulatory BPs might be considered in type 2 diabetic patients.
American Journal of Hypertension, 2005
Background: True resistant hypertension (RH) is defined as uncontrolled office and ambulatory blo... more Background: True resistant hypertension (RH) is defined as uncontrolled office and ambulatory blood pressure (BP) in spite of an optimal regimen with at least three antihypertensive drugs. The aim of this study is to identify, in the office, clinical, laboratory, electrocardiographic, and echocardiographic variables associated with the occurrence of true RH.
Current Hypertension Reports, 2014
With an increased prevalence, resistant hypertension is recognized as an entity with a high cardi... more With an increased prevalence, resistant hypertension is recognized as an entity with a high cardiovascular morbidity and mortality. In a large cohort of patients with resistant hypertension, the crude incidence rate of total cardiovascular events reached 4.32 per 100 patient-years of follow-up (19.6 %), with a cardiovascular mortality of 8.3 % (incidence rate of 1.72 per 100 patient-years). Cardiovascular event rates are significantly higher in resistant hypertensives compared with non-resistant (18.0 % versus 13.5 %). In the same way, the prevalence of established cardiovascular and renal disease, as the asymptomatic organ damage (represented by left ventricular hypertrophy, carotid wall thickening, arterial stiffness, and microalbuminuria) is higher in these patients. Many studies have demonstrated a strong association between damage to these organs with higher blood pressure levels, the diagnosis of true resistant hypertension, and refractory hypertension. All efforts should be employed in order to control blood pressure and also to regress and/or prevent subclinical cardiovascular and renal damage. The focus should be on prevention of cardiovascular and renal complications, improving the prognosis of resistant hypertension.
Journal of Hypertension, 2011
The prognostic importance of a reduced glomerular filtration rate (GFR) is unsettled in resistant... more The prognostic importance of a reduced glomerular filtration rate (GFR) is unsettled in resistant hypertension. The aim was to evaluate GFR and its interaction with microalbuminuria as prognostic predictors in resistant hypertensive patients. In a prospective study, 531 resistant hypertensive patients had albuminuria measured and GFR estimated by Cockroft-Gault (eGFRCG) and Modification of Diet in Renal Disease (MDRD; eGFRMDRD) equations. Primary endpoints were a composite of fatal and nonfatal cardiovascular events, all-cause and cardiovascular mortality. Multiple Cox regression assessed the associations between reduced GFR and endpoints, and interaction with microalbuminuria. After a median follow-up of 4.9 years, 72 patients died, 42 from cardiovascular causes; and 96 cardiovascular events occurred. Decreasing grades of eGFRMDRD were predictors of the composite endpoint with hazard ratios of 2.1 [95% confidence interval (CI) 1.1-3.8], 2.2 (1.2-3.9) and 3.5 (1.4-8.7) for the subgroups with eGFR between 60-89, 30-59 and less than 30 mg/min per 1.73 m, respectively. A decreased eGFRCG was predictive of the composite endpoint only in the lowest GFR subgroup (hazard ratio 2.7, 95% CI 1.0-7.1). The lowest eGFR subgroups were also associated with all-cause mortality, regardless of the estimated equation used. The presence of both reduced eGFR and microalbuminuria significantly increased cardiovascular risk in relation to one or another isolated, with hazard ratios of 3.0 (1.7-5.3), 2.9 (1.5-5.5) and 4.6 (2.2-10.0), respectively for the composite endpoint, all-cause and cardiovascular mortality. A reduced GFR, mainly estimated by the MDRD equation, is an independent predictor of increased cardiovascular morbidity and mortality in resistant hypertension. The combination of a reduced GFR and increased albuminuria identifies patients with a very high cardiovascular risk.
Journal of Hypertension, 2009
The prognostic value of prolonged ventricular repolarization in patients with resistant hypertens... more The prognostic value of prolonged ventricular repolarization in patients with resistant hypertension is unknown. The aim of this prospective study was to investigate the usefulness of electrocardiographic QT-interval parameters as predictors of cardiovascular morbidity and mortality. At baseline, 538 resistant hypertensive patients had five QT-interval components measured in standard 12-lead ECGs: maximum QRS, QTpeak, QTend, JT and Tpeak-to-end-interval durations. Primary endpoints were a composite of fatal and nonfatal cardiovascular events, all-cause and cardiovascular mortalities. Multiple Cox regression assessed the associations between QT-interval parameters and subsequent endpoints. After a median follow-up of 4.8 years, 69 (12.8%) patients died, 46 from cardiovascular causes, and 107 (19.9%) fatal or nonfatal cardiovascular events occurred. After adjustment for several traditional risk factors, including 24-h ambulatory systolic blood pressure, an increment of 1 SD (35 ms) in QTcend-interval was associated with hazard ratios of 1.38 (1.15-1.67), 1.51 (1.16-1.98) and 1.30 (1.03-1.64), respectively, for the composite endpoint, cardiovascular mortality and all-cause mortality. Further adjustment for left ventricular hypertrophy attenuated the relative risks, but they remained significant for cardiovascular mortality (1.45, 1.07-1.97) and for the composite endpoint (1.35, 1.11-1.66). After full adjustment, a prolonged QTcend-interval (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =460 ms) conferred a 1.7-fold (1.1-2.6) higher risk of having a future fatal or nonfatal cardiovascular event. No other QT-interval component added further prognostic information to QTcend-interval duration. Prolonged ventricular repolarization is a risk marker for cardiovascular morbidity and mortality in patients with resistant hypertension, over and beyond traditional cardiovascular risk factors, including ambulatory blood pressure and left ventricular hypertrophy.
Journal of Hypertension, 2010
The ambulatory arterial stiffness index (AASI), derived from ambulatory blood pressure (BP) monit... more The ambulatory arterial stiffness index (AASI), derived from ambulatory blood pressure (BP) monitoring recordings, is an indirect marker of arterial stiffness and a potential predictor of cardiovascular risk. Resistant hypertension is defined as uncontrolled office BP despite the use of at least three antihypertensive drugs. The aim of this prospective study was to investigate the AASI prognostic value in patients with resistant hypertension. At baseline, 547 patients underwent clinical-laboratory, and 24-h ambulatory BP monitoring examinations. AASI was defined as 1 minus the regression slope of DBP on SBP, and was calculated by standard and symmetric regression. Primary endpoints were a composite of fatal and nonfatal cardiovascular events and all-cause and cardiovascular mortalities. Multiple Cox regression was used to assess associations between AASI and subsequent endpoints. After median follow-up of 4.8 years, 101 patients (18.4%) reached the primary endpoint, and 65 all-cause deaths (11.9%) occurred (45 from cardiovascular causes). 24-h AASI was the best independent predictor of composite endpoint (hazard ratio 1.46, 95% confidence interval 1.12-1.92, for increments of 1-SD = 0.14), whereas cardiovascular mortality was best predicted by night-time AASI (hazard ratio 1.73, 95% confidence interval 1.13-2.65), after adjustments for cardiovascular risk factors, including mean ambulatory BPs and nocturnal BP reduction. Symmetric AASI was not superior to standard AASI. In sensitivity analysis, 24-h AASI was a better predictor of cardiovascular outcomes in women, in younger individuals, and in nondiabetic individuals. AASI is a predictor of cardiovascular morbidity and mortality in resistant hypertension, over and beyond traditional risk factors and other ambulatory BP monitoring parameters.
Journal of Hypertension, 2010
The prognostic importance of serial changes in electrocardiographic strain pattern of lateral ST-... more The prognostic importance of serial changes in electrocardiographic strain pattern of lateral ST-depression and T-wave inversion is unclear. The objective was to evaluate the significance of baseline and serial changes in strain pattern as predictors of cardiovascular morbidity and mortality in patients with resistant hypertension. At baseline and during follow-up, 532 resistant hypertensive patients had the presence of strain pattern examined on 12-lead ECGs. Other clinical laboratory, echocardiographic and ambulatory blood pressure data were obtained. Primary endpoints were a composite of total cardiovascular events and mortality. Strokes and coronary heart disease events were secondary endpoints. Multiple Cox regression assessed the associations between strain pattern and subsequent endpoints. At baseline, 115 patients (21.6%) presented the strain pattern and during follow-up, 17 patients regressed and 22 developed new strain pattern. After a median follow-up of 4.8 years, 69 patients died, 46 from cardiovascular causes; and 107 cardiovascular events occurred, 44 strokes and 42 coronary heart disease events. After adjustment for several cardiovascular risk factors, including time-varying ambulatory blood pressures and electrocardiographic voltage criteria of left ventricular hypertrophy, the persistence or development of strain during follow-up was a predictor of the composite endpoint (hazard ratio 1.97, 95% confidence interval 1.19-3.25), all-cause mortality (hazard ratio 1.99, 95% confidence interval 1.10-3.61) and of stroke (hazard ratio 3.09, 95% confidence interval 1.40-6.81). The combination of strain pattern and left ventricular hypertrophy voltage criteria improved stratification of cardiovascular risk. Serial changes in electrocardiographic strain pattern during follow-up predict cardiovascular morbidity and mortality in resistant hypertensive patients. Regression or prevention of the strain pattern during antihypertensive treatment may be a therapeutic goal to improve prognosis.
Journal of Hypertension, 2012
ABSTRACT Objective: Obstructive sleep apnea syndromes (OSAS) increase the risk of hypertension an... more ABSTRACT Objective: Obstructive sleep apnea syndromes (OSAS) increase the risk of hypertension and other cardiovascular diseases. This association seems to be stronger in resistant hypertension (RH), although this has not been systematically examined. As the diagnosis of OSAS is too expensive, there are screening tools to identify patients at high risk, and the Berlin Questionnaire (BQ) is the most widely used. The objective of study is to test the BQ as screening tool for OSAS in RH. Design and Methods: Cross-sectional analysis of 200 resistant hypertensives (67% females, mean age 63 + 9 years) submitted to complete polysomnography. BQ was previously applied by the assistant physician during the routine clinical evaluation. Presence of OSAS was defined by apnea-hypopnea index (AHI) &gt;5 per hour and moderate-severe OSAS by an AHI &gt;15. Statistical analysis included bivariate comparisons between patients with and without moderate-severe OSAS by Mann-Whitney and chi-squared tests. Sensitivity, specificity, positive and negative predictive values and likelihood ratios for QB in detecting OSAS were calculated. Results: 141 patients had OSAS (prevalence rate: 85.5%, 95% CI: 72.4-100%) and 96 patients had moderate-severe OSAS (prevalence: 58.2%, 95% CI: 47.6-71.1%). BQ was applied to all patients and 75% was found at high risk for OSAS. Specificity, sensitivity, positive and negative predictive value of QB in detecting total OSAS was 25%, 75%, 85% and 14%. Furthermore, specificity, sensitivity, positive and negative predictive value of QB in detecting moderate-severe OSAS was 29%, 77%, 60% and 48%. Positive and negative likelihood ratios were 1.08 and 0.79 for moderate-severe OSAS, respectively. Conclusion: In a large cohort of RH patients, BQ had a low to moderate accuracy to identify patients with OSAS. As the prevalence of OSAS in resistant hypertension is very high, all patients should be submitted to polysomnography.
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Papers by Elizabeth S Muxfeldt