Papers by Stefanos Karagiannis
Prognostic information in peripheral arterial disease (PAD) may provide the basis for optimal man... more Prognostic information in peripheral arterial disease (PAD) may provide the basis for optimal management strategies at an early stage. This study aimed to develop a prognostic risk index for long-term mortality in patients with PAD. In a single-center observational cohort study, 2642 patients with an ankle-brachial index of 0.90 or lower were randomly divided into derivation (n = 1332) and validation (n = 1310) cohorts. Cox regression analysis with stepwise backward elimination identified predictors of 1-year, 5-year, and 10-year mortality in the derivation cohort. Weighted points were assigned to each predictor. Index discrimination was determined in both the derivation and validation cohorts. During 10 years of follow-up, 42.2% and 40.4% of patients died in the derivation and validation cohorts, respectively. The risk index for 10-year mortality (+ points) included renal dysfunction (+12), heart failure (+7), ST-segment changes (+5), age greater than 65 years (+5), hypercholesterolemia (+5), ankle-brachial index lower than 0.60 (+4), Q-waves (+4), diabetes (+3), cerebrovascular disease (+3), and pulmonary disease (+3). Statins (-6), aspirin (-4), and beta-blockers (-4) were associated with reduced 10-year mortality. Patients were stratified into low (<0 points), low-intermediate (0-5 points), high-intermediate (6-9 points), and high (>9 points) risk categories, according to risk score. Ten-year mortality rates were 22.1%, 32.2%, 45.8%, and 70.4%, respectively (P < .001) and comparable to mortality in the validation cohort. C statistics demonstrated good discrimination in both the derivation (0.72) and validation cohorts (0.73). A prognostic risk index for long-term mortality stratified patients with PAD into different risk categories. This may be useful for risk stratification, patient counseling, and medical decision making.
Annales de Chirurgie Vasculaire, 2007
ABSTRACT Le contrôle glycémique est peut être un facteur de risque sous-estimé chez les malades d... more ABSTRACT Le contrôle glycémique est peut être un facteur de risque sous-estimé chez les malades diabétiques ayant une artériopathie périphérique (AP). Un traitement au long cours par statines peut améliorer le contrôle glycémique et l'évolution de ces malades. Dans une étude observationnelle de cohorte de 425 malades diabétiques consécutifs ayant une AP, le traitement au long cours par statines a été noté, l'indice cheville-bras a été mesuré et des mesures répétées d'hémoglobine glyquée (HbA1c) réalisées. Au cours du suivi (médiane 7 ans), la mortalité de toutes causes et la mortalité cardiaque sont survenues respectivement dans 37% et 22% des cas. Les diminutions de l'HbA1c et la variabilité de l'HbA1c ont prédit indépendamment l'évolution en plus des valeurs de base de l'indice cheville-bras. Les malades sous traitement chronique par statines avaient davantage de chance d'avoir des HbA1c diminuées (risque relatif (RR) = 1,86, intervalle de confiance (IC) à 95% = 1,27-2,74 et des valeurs d'HbA1c inférieures à 7% (RR = 2,58, IC 95% = 1,49-4,48) au cours du suivi. Les statines étaient également associées de façon significative avec une mortalité de toutes causes plus faible (RR = 0,39, IC 95% = 0,26-0,61) et un taux de décès cardiaque plus faible (RR = 0,40, IC 95% = 0,24-76). D'après les résultats de la présente étude observationnelle, nous concluons que des mesures répétées de l'HbA1c peuvent améliorer la stratification des risques chez les malades diabétiques ayant une AP. De plus, le traitement par statines est associé à un meilleur contrôle glycémique et à de meilleurs résultats à long terme.
European Journal of Echocardiography, 2007
We tested the hypothesis that shortening of diastolic pressure half time (PHT) of left anterior d... more We tested the hypothesis that shortening of diastolic pressure half time (PHT) of left anterior descending (LAD) coronary flow in patients with old reperfused anterior myocardial infarction (MI) is related to the presence of permanent myocardial damage of the reperfused area. We studied 49 patients divided into: group A: 15 patients with previous anterior MI and evidence of myocardial scar; group B: 10 patients with previous anterior MI and no evidence of myocardial scar and group C: 24 patients without anterior MI. All patients underwent coronary angiography at least 6 months after an index event and any reperfusion procedure. Group A patients had lower PHT (199 +/- 62 ms) than group C (377 +/- 103 ms, p = 0.0001) and group B (316 +/- 154 ms, p = 0.029) patients. No other LAD flow velocity parameter differed among the 3 groups. A PHT value of 265 ms discriminated patients with scarred anterior wall with a sensitivity of 79% and a specificity of 94% (0.88, p < 0.001). Shortening of the LAD flow diastolic PHT in patients with remote, reperfused anterior MI reflects scarred myocardial tissue in the anteroapical wall while patients who maintain diastolic wall thickness after an acute coronary syndrome have PHT similar to patients without anterior MI.
European journal of echocardiography : the journal of the Working Group on Echocardiography of the European Society of Cardiology, 2007
Dobutamine stress echocardiography is a commonly used imaging modality for the diagnosis of coron... more Dobutamine stress echocardiography is a commonly used imaging modality for the diagnosis of coronary artery disease and the detection of myocardial viability. The major limitations are that it is operator dependent and that the analysis is subjective and qualitative resulting in interobserver variability. It is also tedious and time consuming. Consequently, several quantitative approaches have been proposed, such as acoustic quantification and color kinesis but none of these has proved to be fully quantitative. In this manuscript we describe the development of a new, quantitative technique based on tracking of both endocardium and epicardium providing information of endocardial excursion and myocardial thickening, a crucial parameter of wall function evaluation. Preliminary data indicate that the method is practical and feasible, but clinical trials are required to prove whether it will improve the sensitivity and specificity of dobutamine stress echocardiography.
European journal of echocardiography : the journal of the Working Group on Echocardiography of the European Society of Cardiology, 2008
Complications of any mechanical prosthesis include thrombus or pannus formation. In our case repo... more Complications of any mechanical prosthesis include thrombus or pannus formation. In our case report we demonstrate that prosthetic aortic valve regurgitation due to pannus formation may be intermittent and non-cyclic in pattern and therefore not obvious at the time of original clinical examination. Under these conditions and as transesophageal echocardiography cannot be repeated promptly, transthoracic 2-D and Doppler echocardiography should be available at any time when symptoms occur and present the method of choice for acute patient evaluation. Thrombolysis seems to be the first treatment of choice in case of thrombus formation and re-do surgery in case of pannus formation.
Heart (British Cardiac Society), 2003
To measure the distance between the mitral leaflet coaptation point and the mitral annulus (CPMA)... more To measure the distance between the mitral leaflet coaptation point and the mitral annulus (CPMA) and assess the relation of this index to structural and functional characteristics of the failing left ventricle. Echocardiographic indices and CPMA were measured at baseline and again during dobutamine infusion and leg lifting. Left ventricular diastolic and systolic dimensions, left ventricular ejection fraction (LVEF) by Simpson's rule, mitral annulus dimension, and E point septal separation were correlated with CPMA. Tertiary referral centre. The total study population of 129 patients included 94 with LVEF < 35% and 35 with LVEF 35%-45%; 76 had coronary artery disease and 53 had dilated cardiomyopathy. A dobutamine infusion was given in 18 patients and preload increase by leg lifting in 28. Correlations between CPMA and contractility indices at baseline and during interventions. CPMA was correlated with left ventricular diastolic dimension (r = 0.52), left ventricular systoli...
Nephrology Dialysis Transplantation, 2007
Dobutamine stress echocardiography (DSE) is used for risk stratification of patients with suspect... more Dobutamine stress echocardiography (DSE) is used for risk stratification of patients with suspected coronary artery disease (CAD). However, the prognostic value of DSE among the entire strata of renal function has yet to be determined. We assessed the prognostic value of renal function relative to DSE findings. We studied 2292 patients, divided into 729 (32%) patients with normal renal function [creatinine clearance (CrCl) &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;90 ml/min] and 1563 (68%) with renal dysfunction, classified as mild (CrCl: 60-90 ml/min) in 933, moderate (CrCl: 30-60 ml/min) in 502 and severe (CrCl &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 30 ml/min) in 128 patients. All patients underwent DSE for the evaluation of known or suspected CAD and were followed for a mean of 8 years. New wall motion abnormalities during DSE and mildly, moderately and severely abnormal CrCl were powerful independent predictors for all-cause mortality, cardiac death and hard cardiac events (cardiac death and non-fatal myocardial infarction). Kaplan-Meier curves demonstrated that patients with normal DSE and renal dysfunction have greater probability for cardiac death and hard cardiac events compared to those with normal renal function. The warranty of a normal DSE in the presence of moderate renal dysfunction was 15 and 36 months for 10 and 20% risk for cardiac death and hard cardiac events, respectively. The presence and severity of renal dysfunction has additional independent prognostic value over DSE findings. The low-risk warranty period after a normal DSE is determined by the severity of renal dysfunction.
Journal of the American Society of Nephrology, 2007
Patients with peripheral arterial disease (PAD) are at increased risk for ESRD and cardiovascular... more Patients with peripheral arterial disease (PAD) are at increased risk for ESRD and cardiovascular events. The primary objective was to assess the association between ankle-brachial index (ABI) values and renal outcome. The secondary objective was to evaluate whether statins and angiotensin-converting enzyme inhibitors (ACEI) are associated with improved renal and cardiovascular outcome in patients with PAD. In a prospective observational cohort study of 1940 consecutive patients with PAD, ABI was measured and chronic statin and ACEI therapy was noted at baseline. Serial creatinine concentrations were obtained at baseline, 6 mo, and every year after enrollment. End points were ESRD, all-cause mortality, and cardiac events during a median follow-up period of 8 yr. Baseline estimated GFR <60 ml/min per 1.73 m 2 was assessed in 27% of patients. ESRD, all-cause mortality, and cardiac events occurred in 10, 46, and 31% of patients, respectively. In multivariate analysis, a lower baseline ABI was significantly associated with a higher progression rate of ESRD (hazard ratio [HR] per 0.10 decrease 1.34; 95% confidence interval [CI] 1.21 to 1.49). Chronic use of statins and ACEI were significantly associated with lower ESRD (HR 0.41 [95% CI 0.28 to 0.63] and 0.74 [95% CI 0.54 to 0.98], respectively), mortality (HR 0.66; [95% CI 0.55 to 0.82] and 0.84 [95% CI 78 to 0.95], respectively), and cardiac events (HR 0.71 [95% CI 0.56 to 0.91] and 0.81 [95% CI 0.68 to 0.96], respectively). In patients with PAD, low ABI values independently predict the onset of ESRD. Less progression toward ESRD and improved cardiovascular outcome was observed among patients who were on long-term statins and ACEI.
Journal of the American College of Cardiology, 2007
This study sought to examine whether higher statin doses and lower low-density lipoprotein (LDL) ... more This study sought to examine whether higher statin doses and lower low-density lipoprotein (LDL) cholesterol are associated with improved cardiac outcome in vascular surgery patients.
International Journal of Cardiology, 2006
To detect origin and course and to evaluate viability in patients with anomalous RCA. 3D coronary... more To detect origin and course and to evaluate viability in patients with anomalous RCA. 3D coronary MR angiography and viability study using gadolinium-enhanced magnetic resonance imaging (Gd-MRI) was performed. A tertiary hospital center. Four patients, selected from the catheter lab, were studied. Anomalous RCA from the left sinus of Valsalva was identified in all patients. Inferior myocardial infarction was documented in three patients. Magnetic resonance imaging can non-invasively identify anomalous RCA and perform viability study in the same examination.
International Journal of Cardiology, 2008
In patients undergoing exercise testing a hypotensive response is associated with a poor prognosi... more In patients undergoing exercise testing a hypotensive response is associated with a poor prognosis. There is limited information regarding the prognostic significance of hypotension during dobutamine stress test. This study investigates the association between a severe hypotensive response during DSE and long-term prognosis. Patients (3381) underwent dobutamine stress echocardiography (DSE). Blood pressure was measured automatically at rest and at the end of every dose-step. Wall motion was scored using a 16-segement, 5-point score. Ischemia was defined by the presence of new wall motion abnormalities. Hypotensive response during DSE was defined as mild (MHR) when systolic blood pressure (SBP) dropped &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;20 mmHg between rest and peak stress, and severe (SHR) when SBP dropped &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;20 mmHg. During follow-up all cause mortality and MACE (cardiac death or non-fatal myocardial infarction) were noted. MHR and SHR occurred in 936 (28%) and 521 (15%) patients, respectively. Independent predictors of SHR were older age, new or worsening wall motion abnormalities and history of hypertension. During follow-up of 4.5 (+/-3.3) years, 920 patients died, of which 555 due to cardiac causes, and 713 patients experienced a MACE. After adjustment for baseline characteristics and DSE results SHR during DSE was independently associated with increased long-term cardiac death (HR: 1.3, 95% CI: 1.03-1.6) and MACE (HR: 1.34, 95% CI: 1.1-1.6), while MHR was not associated with a worse outcome. Severe hypotensive response during DSE independently predicts cardiac death and MACE in patients with known or suspected coronary artery disease.
European Journal of Heart Failure, 2007
Myocardial viability assessment in severely dysfunctional segments by dobutamine stress echocardi... more Myocardial viability assessment in severely dysfunctional segments by dobutamine stress echocardiography (DSE) is less sensitive than nuclear scanning. To assess the additional value of using the recovery phase of DSE after acute beta-blocker administration for identifying viable myocardium. The study included 49 consecutive patients with ejection fraction (LVEF)&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;or=35%. All patients underwent DSE evaluation at low-high dose and during recovery phase, and dual-isotope single photon emission tomography (DISA-SPECT) evaluation for viability of severely dysfunctional segments. Patients with &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=4 viable segments were considered viable. Coronary revascularization followed within 3 months in all patients. Radionuclide evaluation of LVEF was performed before and 12 months after revascularization. Viability with DISA-SPECT was detected in 463 (59%) segments, while 154 (19.7%) segments presented as scar. The number of viable segments increased from 415 (53%) at DSE to 463 (59%) at DSE and recovery, and the number of viable patients increased from 43 to 49 respectively. LVEF improved by &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=5% in 27 patients. Multivariate regression analysis showed that, DSE with recovery phase was the only independent predictor of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=5% LVEF improvement after revascularization (OR 14.6, CI 1.4-133.7). In this study, we demonstrate that the recovery phase of DSE has an increased sensitivity for viability estimation compared to low-high dose DSE.
European Journal of Clinical Pharmacology, 2006
Objective: The prevention of contrast-mediated nephropathy (CMN), which accounts for considerable... more Objective: The prevention of contrast-mediated nephropathy (CMN), which accounts for considerable morbidity and mortality, remains a vexing problem. Contrast induced renal vasoconstriction is believed to play a pivotal role in the CMN mechanism. The aim of this pilot study was to examine the safety and efficacy of two doses of the prostacyclin analogue iloprost in preventing CMN in high-risk patients undergoing a coronary procedure. Methods: Forty-five patients undergoing coronary angiography and/or intervention who had a serum creatinine concentration ≥1.4 mg/dL were randomized to receive iloprost at 1 or 2 ng/kg/min or placebo, beginning 30-90 minutes before and terminating 4 hours after the procedure. CMN was defined by an absolute increase of serum creatinine ≥0.5 mg/dL or a relative increase of ≥25% measured 2 to 5 days after the procedure. Study drug infusion was discontinued in 2 patients in the low-dose iloprost group due to flush/nausea and in 5 patients in the high-dose group due to severe hypotension. Results: The mean creatinine concentration change in the placebo group (0.02 mg/dL) was unfavorable compared to that in the low-dose iloprost group (−0.11 mg/dL; p=0.08) and high-dose iloprost group (−0.23 mg/dL; p=0.048). The difference between the absolute changes in creatinine clearance was favorable compared to placebo for both the low (mean difference 6.1 mL/min, 95%CI −0.5 to 12.8 mL/min, p=0.07) and the high-dose iloprost group (11.8 mL/min, 95%CI 4.7 to 18.8 mL/min, p=0.002). Three cases of CMN were recorded; all in the placebo group (p=0.032). Conclusions: The results of this pilot study suggest that prophylactic administration of iloprost may effectively prevent CMN, but higher dosages are connected with substantial tolerability issues.
Diabetic Medicine, 2008
Cardiac morbidity and mortality is high in patients undergoing high-risk surgery. This study inve... more Cardiac morbidity and mortality is high in patients undergoing high-risk surgery. This study investigated whether impaired glucose regulation and elevated glycated haemoglobin (HbA(1c)) levels are associated with increased cardiac ischaemic events in vascular surgery patients. Baseline glucose and HbA(1c) were measured in 401 vascular surgery patients. Glucose &amp;amp;lt; 5.6 mmol/l was defined as normal. Fasting glucose 5.6-7.0 mmol/l or random glucose 5.6-11.1 mmol/l was defined as impaired glucose regulation. Fasting glucose &amp;amp;gt; or = 7.0 or random glucose &amp;amp;gt; or = 11.1 mmol/l was defined as diabetes. Perioperative ischaemia was identified by 72-h Holter monitoring. Troponin T was measured on days 1, 3 and 7 and before discharge. Cardiac death or Q-wave myocardial infarction was noted at 30-day and longer-term follow-up (mean 2.5 years). Mean (+/- sd) level for glucose was 6.3 +/- 2.3 mmol/l and for HbA(1c) 6.2 +/- 1.3%. Ischaemia, troponin release, 30-day and long-term cardiac events occurred in 27, 22, 6 and 17%, respectively. Using subjects with normal glucose levels as the reference category, multivariate analysis revealed that patients with impaired glucose regulation and diabetes were at 2.2- and 2.6-fold increased risk of ischaemia, 3.8- and 3.9-fold for troponin release, 4.3- and 4.8-fold for 30-day cardiac events and 1.9- and 3.1-fold for long-term cardiac events. Patients with HbA(1c) &amp;amp;gt; 7.0% (n = 63, 16%) were at 2.8-fold, 2.1-fold, 5.3-fold and 5.6-fold increased risk for ischaemia, troponin release, 30-day and long-term cardiac events, respectively. Impaired glucose regulation and elevated HbA(1c) are risk factors for cardiac ischaemic events in vascular surgery patients.
Coronary Artery Disease, 2007
The aim of this study is to determine the prevalence and prognosis of unrecognized myocardial inf... more The aim of this study is to determine the prevalence and prognosis of unrecognized myocardial infarction (MI) and silent myocardial ischemia in vascular surgery patients. In a cohort of 1092 patients undergoing preoperative dobutamine stress echocardiography and noncardiac vascular surgery, unrecognized MI was determined by rest wall motion abnormalities in the absence of a history of MI. Silent myocardial ischemia was determined by stress-induced wall motion abnormalities in the absence of angina pectoris. Beta blockers and statins were noted at baseline. During follow-up (mean: 6+/-4 years), all-cause mortality and major cardiac events (cardiac death or nonfatal MI) were noted. The prevalence of unrecognized MI and silent myocardial ischemia was 23 and 28%, respectively. Both diabetes and heart failure were important predictors of unrecognized MI and silent myocardial ischemia. During follow-up, all-cause mortality occurred in 45% and major cardiac events in 23% of patients. In multivariate analysis, unrecognized MI and silent myocardial ischemia were significantly associated with increased risk of mortality [hazard ratio (HR), 1.86; 95% confidence interval (CI), 1.53-2.25 and HR, 1.74; 95% CI, 1.46-2.06, respectively] and major cardiac events (HR, 2.15; 95% CI, 1.59-2.92 and HR, 1.86; 95% CI, 1.43-2.41, respectively). In patients with unrecognized MI, beta-blockers and statins were significantly associated with improved survival. Statins improved survival in patients with silent myocardial ischemia. In patients undergoing major vascular surgery, unrecognized MI and silent myocardial ischemia are highly prevalent (23 and 28%) and associated with increased long-term mortality and major cardiac events.
Coronary Artery Disease, 2007
ABSTRACT Carotid artery stenting (CAS) is less invasive than endarterectomy. This study examined ... more ABSTRACT Carotid artery stenting (CAS) is less invasive than endarterectomy. This study examined differences in perioperative myocardial ischemia, troponin T release and clinical cardiac events in patients undergoing CAS compared with endarterectomy. In an observational study, CAS was performed in 24 and carotid endarterectomy in 44 patients. Before surgery, clinical risk factors were noted and dobutamine stress echocardiography was performed for cardiac risk assessment. Perioperative continuous 72-h 12-lead electrocardiographic monitoring was used for myocardial ischemia detection. Troponin T (&gt;0.03 ng/ml) was measured on postoperative days 1, 3, 7 or before discharge. Cardiac events (cardiac death or Q-wave myocardial infarction) were noted during hospital stay and during follow-up (mean: 1.2 years). No significant differences were observed between patients with CAS and endarterectomy in terms of baseline clinical characteristics, dobutamine stress echocardiography results and cardiovascular medication. Perioperative myocardial ischemia was detected in nine patients (13%), perioperative troponin T release in seven patients (10%), early cardiac events in one patient (1%) and late cardiac events in three patients (4%). Significantly less perioperative myocardial ischemia was observed in patients with CAS compared with endarterectomy (0 versus 21%, P=0.02). Troponin T release was also significantly lower in CAS, compared with endarterectomy (0 versus 16%, P=0.04). Early (0 versus 2%, P=0.5) and late (0 versus 7%, P=0.2) cardiac events were lower after CAS, compared with endarterectomy, although these differences were not significant. CAS is associated with a lower incidence of perioperative myocardial ischemia and troponin T release, compared with endarterectomy.
Coronary Artery Disease, 2007
To assess the prognostic value of wall motion abnormalities during the recovery phase of dobutami... more To assess the prognostic value of wall motion abnormalities during the recovery phase of dobutamine stress echocardiography in addition to wall motion abnormalities at peak stress. Wall motion abnormalities were assessed at peak and during recovery phase of dobutamine stress echocardiography in 187 consecutive patients, who were followed for occurrence of cardiac events. During follow-up (mean 36+/-28 months), 19 patients (10%) died from cardiac causes, 34 (18%) patients suffered nonfatal myocardial infarction, and 77 (41%) patients underwent late revascularization. Univariable predictors of cardiac events by Cox regression analysis were age (hazard ratio: 1.01; confidence interval: 1.00-1.03), dyslipidemia (hazard ratio: 1.41; confidence interval: 1.02-1.95), rest wall motion abnormalities (hazard ratio: 1.37; confidence interval: 1.14-1.64), new wall motion abnormalities (hazard ratio: 1.18; confidence interval: 0.95-1.45) at peak and new wall motion abnormalities (hazard ratio: 1.33; confidence interval: 1.11-1.59) at recovery phase of dobutamine stress echocardiography. The best multivariable model to predict cardiac events included new wall motion abnormality (hazard ratio: 5.34; confidence interval: 1.71-16.59) at recovery phase of dobutamine stress echocardiography, after controlling for clinical and peak dobutamine stress echocardiography data. Myocardial ischemia at recovery phase of dobutamine stress echocardiography is an independent predictor of cardiac events and has an incremental value when added to ischemia at peak.
Coronary Artery Disease, 2007
This study was conducted to determine the association between baseline N-terminal pro-B-type natr... more This study was conducted to determine the association between baseline N-terminal pro-B-type natriuretic peptide (NT-proBNP) and myocardial ischemia, troponin T release and heart rate variability (HRV) in patients undergoing major vascular surgery. In a prospective study, 182 vascular surgery patients were evaluated by clinical risk factors, dobutamine stress echocardiography and baseline NT-proBNP levels. Myocardial ischemia was detected by continuous 12-lead electrocardiographic monitoring starting 1 day before to 2 days after surgery. Troponin T (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;0.03 ng/ml) was measured on day 1, 3 and 7 postoperatively and before discharge. HRV was measured at the day prior to surgery. The median NT-proBNP level was 184 ng/l (interquartile range: 79-483 ng/l). Myocardial ischemia was detected in 21% and troponin T release in 17% of patients. After adjustment for clinical risk factors and stress echocardiography results, higher NT-proBNP levels (per 1 ng/l increase in the natural logarithm of NT-proBNP) were associated with a higher incidence of myocardial ischemia (odds ratio: 1.59, 95% confidence interval: 1.21-2.08, P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and troponin T release (odds ratio: 1.76, 95% confidence interval: 1.33-2.34, P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). The optimal cutoff value of NT-proBNP to predict ischemia and/or troponin T release was 270 ng/l (area under the curve: 0.70). Higher baseline NT-proBNP levels were also associated with a larger ischemic burden at electrocardiographic monitoring (r=0.22, P=0.03). No significant correlation, however, was found between NT-proBNP and preoperative HRV (r=-0.024, P=0.78). Elevated baseline NT-proBNP levels are significantly associated with perioperative myocardial ischemia and troponin T release, but not with preoperative HRV in patients undergoing major vascular surgery.
Archives of Internal Medicine, 2007
Prognostic information in peripheral arterial disease (PAD) may provide the basis for optimal man... more Prognostic information in peripheral arterial disease (PAD) may provide the basis for optimal management strategies at an early stage. This study aimed to develop a prognostic risk index for long-term mortality in patients with PAD. In a single-center observational cohort study, 2642 patients with an ankle-brachial index of 0.90 or lower were randomly divided into derivation (n = 1332) and validation (n = 1310) cohorts. Cox regression analysis with stepwise backward elimination identified predictors of 1-year, 5-year, and 10-year mortality in the derivation cohort. Weighted points were assigned to each predictor. Index discrimination was determined in both the derivation and validation cohorts. During 10 years of follow-up, 42.2% and 40.4% of patients died in the derivation and validation cohorts, respectively. The risk index for 10-year mortality (+ points) included renal dysfunction (+12), heart failure (+7), ST-segment changes (+5), age greater than 65 years (+5), hypercholesterolemia (+5), ankle-brachial index lower than 0.60 (+4), Q-waves (+4), diabetes (+3), cerebrovascular disease (+3), and pulmonary disease (+3). Statins (-6), aspirin (-4), and beta-blockers (-4) were associated with reduced 10-year mortality. Patients were stratified into low (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0 points), low-intermediate (0-5 points), high-intermediate (6-9 points), and high (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;9 points) risk categories, according to risk score. Ten-year mortality rates were 22.1%, 32.2%, 45.8%, and 70.4%, respectively (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001) and comparable to mortality in the validation cohort. C statistics demonstrated good discrimination in both the derivation (0.72) and validation cohorts (0.73). A prognostic risk index for long-term mortality stratified patients with PAD into different risk categories. This may be useful for risk stratification, patient counseling, and medical decision making.
Archives of Gerontology and Geriatrics, 2009
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Papers by Stefanos Karagiannis