Papers by Andreas Pittaras
Springer eBooks, 2016
Hypertensive heart disease includes chronic maladaptations of cardiac structure and function caus... more Hypertensive heart disease includes chronic maladaptations of cardiac structure and function caused by the direct and/or indirect effects of uncontrolled and prolonged elevations of arterial pressure. Reductions in blood pressure with most antihypertensive agents or lifestyle interventions lead to improvements in cardiac function, reversal of the structural maladaptations and improvement in cardiovascular prognosis. This chapter addresses the impact of increased physical activity or structured aerobic exercises on blood pressure control and hypertensive heart disease.
Journal of Hypertension, Jun 1, 2022
Journal of the American College of Cardiology, Mar 1, 2003
rehabilitation on endothelial function, &dative stress and antioxidant defenses in coronary arter... more rehabilitation on endothelial function, &dative stress and antioxidant defenses in coronary artery disease. Methods: Ten coronary artery disease patients underwent 12 weeks of exercise training as part of a standard cardiac rehabilitation program and ten control patients received 12 weeks of standard of care. Flow mediated dilation (FMD) of the brachial artery was assessed during reactive hyperemia using ultrasound at baseline and following the 12 week treatment period. Additionally, blood was drawn at baseline and 12 weeks for analysis of H-isoprostane-F,, (6-iso-PGF&) and plasma nitrite/nitrate (NOx) and superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities. Results: Control Exercise Trained BSLN 12 Weeks BSLN 12 Weeks FMD (%) 6.Ot2.4 6.4*2.3 7.222.1 11.2+3.3' NOx (prmI/L) 29.13+6.22 30.16&.64 26.62a6.03 34.7Ozt6.67' 8-iso-PGFPa (pglml) 455.9*60.7 462.Ozt60.5 490.5t140.5 406.7i109.6" SOD (U/ml) 1.50*0.19 1.46+0.09 1.49*0.15 1.64*0.31' GPx l&mol/ml) 0.149t0.014 0.147*0.015 0.140*0.014 0.144*0.010 Values are mean * SE. *p<O.O5 vs. BSLN. Conclusions: This study demonstrates that endurance exercise training in coronary artery disease improves endothelial function. The improvement in endothelial function in these patients following exercise training may be due to increased nitric oxide production and reductions in oxidative stress leading to increased nitric oxide availability.
Increased cardiac wall thickness, left ventricular (LV) chamber enlargement, and left ventricular... more Increased cardiac wall thickness, left ventricular (LV) chamber enlargement, and left ventricular hypertrophy (LVH) are characteristics of chronic, vigorous exercise endured by athletes and commonly referred to as “the athlete’s heart.” These cardiac structural and functional adaptations are specific to the workload demands imposed upon the myocardium, are considered normal physiologic responses, and are not associated with adverse prognosis. However, in young athletes, a thorough examination should be performed by a cardiologist to differentiation between physiological LVH (athlete’s heart) and hypertrophic cardiomyopathy, the commonest cause of non-traumatic exercise-related sudden cardiac death. Perhaps exercise-induced cardiac structural adaptations that improve cardiac efficiency and ultimately accommodate the imposed physiologic demand should be referred to as eutrophic. Conversely, hypertrophic cardiac adaptations should be considered exclusively those imposed by pathophysiologic and encroach upon cardiac efficiency, ultimately leading to compromised cardiac dysfunction and even death.
Progress in Cardiovascular Diseases, Jul 1, 2021
OBJECTIVE To assess the cardiorespiratory fitness (CRF) impact on the association between exercis... more OBJECTIVE To assess the cardiorespiratory fitness (CRF) impact on the association between exercise blood pressure (BP) and mortality risk. PATIENTS AND METHODS We assessed CRF in 15,004 US Veterans (mean age 57.5 ± 11.2 years) who completed a standardized treadmill test between January 1, 1988 and July 28, 2017 and had no evidence of ischemia. They were classified as Unfit or Fit according to the age-specific metabolic equivalents (METs) achieved <50% (6.2 ± 1.6 METs; n = 8440) or ≥ 50% (10.5 ± 2.4 METs; n = 6264). To account for the impact of resting systolic BP (SBP) on outcomes, we calculated the difference (Peak SBP-Resting SBP) and termed it SBP-Reserve. We noted a significant increase in mortality associated with SBP-Reserve ≤52 mmHg and stratified the cohort accordingly (SBP-Reserve ≤52 mmHg and > 52 mmHg). We applied multivariable Cox models to estimate hazard ratios (HR) and 95% confidence interval (CIs) for outcomes. RESULTS Mortality risk was significantly elevated only in Unfit individuals with SBP-Reserve ≤52 mmHg compared to those with SBP-Reserve >52 mmHg (HR = 1.35; CI: 1.24-1.46; P < 0.001). We then assessed the CRF and SBP-Reserve interaction on mortality risk with Fit individuals with SBP-Reserve >52 mmHg serving as the referent. Mortality risk was 92% higher (HR = 1.92%; 95% CI: 1.77-2.09; P < 0.001) in Unfit individuals with SBP-Reserve ≤52 mmHg and 47% higher (HR = 1.47; 95% CI: 1.33-1.62; P < 0.001) in those with SBP-Reserve >52 mmHg. CONCLUSION Low CRF was associated with increased mortality risk regardless of peak exercise SBP. The risk was substantially higher in individuals unable to augment their exercise SBP >52 mmHg beyond resting levels.
PubMed, Sep 22, 2011
Introduction: Torsional and longitudinal deformations are essential components of left ventricula... more Introduction: Torsional and longitudinal deformations are essential components of left ventricular (LV) performance. We believe that a precise assessment of LV function must take into account both LV torsion (LVtor) and global longitudinal strain (LVε). Therefore, we investigated with speckle tracking echocardiography the value of a new parameter, LVtor × LVε, for assessing LV function in dilated cardiomyopathy (DCM) and validated it against N-terminal pro-brain natriuretic peptide (NTproBNP). Methods: Echocardiography was performed simultaneously with NTproBNP determination in 55 consecutive patients with DCM in sinus rhythm. The ratio of early diastolic transmitral velocity to early mitral annular diastolic velocity (E/E') was measured. LVtor was defined as the ratio between LV twist (LVtw) and LV enddiastolic longitudinal length. LVtw (net difference between rotation angles at base and apex) was obtained from parasternal apical and basal short-axis planes. LVε was obtained by averaging longitudinal peak systolic strain of all 17 LV-segments (from apical planes). Results: Log-transformed NTproBNP correlated significantly with LVε (r=0.56, p<0.001), E/E' (r=0.52, p<0.001), LVtor (r=-0.41, p=0.003), LVtw (r=-0.38, p=0.004) and LV ejection fraction (r=-0.37, p=0.005). LVtor × LVε had the strongest correlation with log-NTproBNP (r=0.71, p<0.001). LVtor × LVε was a better predictor of NTproBNP levels >900 pg/ml (sensitivity 73%, specificity 82%) than LVε, E/E', LVtw, LVtor and LV ejection fraction (each p<0.05). Conclusions: This study demonstrates that in patients with DCM in sinus rhythm, the evaluation of LV function can be accurately accomplished by using a new speckle tracking index, LVtor × LVε.
Current Vascular Pharmacology, Mar 31, 2014
The prevalence of resistant hypertension and existing limitations in antihypertensive drug therap... more The prevalence of resistant hypertension and existing limitations in antihypertensive drug therapy renders the interventional management of hypertension an attractive alternative. Carotid baroreceptors have been traditionally thought to be implicated only in short-term blood pressure regulation; however recent evidence suggests that the baroreceptors might play an important role even in the long-term blood pressure regulation. Electrical baroreflex stimulation appears safe and effective and might represent a useful adjunct to medical therapy in patients with resistant hypertension. This review endeavors to summarize the complex pathophysiology of blood pressure regulation, to describe the baroreflex circuit, its anatomy and physiology, to present previous data refuting a role for the baroreceptors in the long-term control of blood pressure and recent animal and human data suggesting an effective role of carotid baroreceptor activation in long-lasting blood pressure reduction. In this paper we attempt to critically evaluate existing information in this area and provide the scientific basis for carotid baroreceptor stimulation in the management of resistant hypertension.
Mayo Clinic Proceedings, May 1, 2016
To assess the association between exercise capacity and the risk of developing atrial fibrillatio... more To assess the association between exercise capacity and the risk of developing atrial fibrillation (AF). A symptom-limited exercise tolerance test was conducted to assess exercise capacity in 5962 veterans (mean age, 56.8±11.0 years) from the Veterans Affairs Medical Center, Washington, DC. None had evidence of AF or ischemia at the time of or before undergoing their exercise tolerance test. We established 4 fitness categories based on age-stratified quartiles of peak metabolic equivalent task (MET) achieved: least fit (4.9±1.10 METs; n=1446); moderately fit (6.7±1.0 METs; n=1490); fit (7.9±1.0 METs; n=1585), and highly fit (9.3±1.2 METs; n=1441). Multivariable Cox proportional hazards regression models were used to compare the AF-exercise capacity association between fitness categories. During a median follow-up period of 8.3 years, 722 (12.1%) individuals developed AF (14.5 per 1000 person-years; 95% CI, 13.9-15.9 per 1000 person-years). Exercise capacity was inversely related to AF incidence. The risk was 21% lower (hazard ratio, 0.79; 95% CI, 0.76-0.82) for each 1-MET increase in exercise capacity. Compared with the least fit individuals, hazard ratios were 0.80 (95% CI, 0.67-0.97) for moderately fit individuals, 0.55 (95% CI, 0.45-0.68) for fit individuals, and 0.37 (95% CI, 0.29-0.47) for highly fit individuals. Similar trends were observed in those younger than 65 years and those 65 years or older. Increased fitness is inversely and independently associated with the reduced risk of developing AF. The decrease in risk was graded and precipitous with only modest increases in exercise capacity. These findings counter previous suggestions that even moderate increases in physical activity, as recommended by national and international guidelines, increase the risk of AF, with marked protection against AF noted with increasing levels of fitness.
Journal of the American College of Cardiology, Mar 1, 2023
Medicine and Science in Sports and Exercise, May 1, 1999
American Journal of Hypertension, Nov 1, 2001
The aim of this study was to evaluate the effects of a fixed, low-dose combination of sustained r... more The aim of this study was to evaluate the effects of a fixed, low-dose combination of sustained release (SR) verapamil and trandolapril in patients (pts) with mild to severe essential hypertension uncontrolled by monotherapy. The study material consisted of 138 (77 women, 61 men; mean age 51.6Ϯ10.3 years, ranged 21-70) pts. After a placebo wash-out period of one week, all pts had taken a fixed combination of verapamil SR 180 mg and trandolapril 2 mg (Tarka®) once a day for 6 weeks. The sitting systolic and diastolic blood pressures (BPs) were significantly reduced from 168.5Ϯ15.6/ 100.3Ϯ8.1 mmHg to 137.6Ϯ13.1/85.1Ϯ8.1 mmHg at the end of the trial (pϽ0.001 and pϽ0.001). The percentage of reduction for systolic and diastolic BPs were 19% and 17%, respectively. The target value of BP (BPϽ140/90 mm Hg and reduction of diastolic BPϾ10 mm Hg) was achieved in 70% of the pts at the end of 6 weeks. The heart rate was reduced slightly, but significantly (pϽ0.01). The left ventricular mass detected by echocardiography was significantly reduced from 124.0Ϯ32.09 g to 118.2Ϯ25.9 g (pϽ0.001), and the E/A ratio of mitral inflow was increased from 0.9Ϯ0.4 to 1.0Ϯ0.4 (pϽ0.01). Adverse effects developed in 17 (12%) pts (cough in 3 pts, headache in 5 pts, palpitations in 2 pts, constipation in 3 pts, tinnutus in 2 pts, edema in 1 patient and flushing in 1 patient), 2 of them were withdrawn from the trial due to the side effects (1 patient with flushing and 1 patient with cough). No clinically relevant changes in laboratory parameters (glucose, urea, creatinine, uric acid, electrolytes, GOT, GPT, alkaline phosphatase, total cholesterol, HDL-cholesterol, VLDL-cholesterol, triglycerides, protein) have been detected. In conclusion, it was confirmed that a fixed verapamil SR and trandolapril combination has 1. Superior antihypertensive efficacy compared to monotherapy, 2. High efficacy with excellent tolerability and safety, 3. A neutral impact on the metabolic parameters, and 4. Regressive effect on left ventricular hypertrophy.
Journal of Clinical Hypertension, Nov 1, 2009
Angiotensin‐converting enzyme (ACE) inhibitors have been extensively used for the treatment of pa... more Angiotensin‐converting enzyme (ACE) inhibitors have been extensively used for the treatment of patients with cardiovascular disease, but several concerns have been raised about their efficacy in African American (AA) patients with heart failure, hypertension, and left ventricular hypertrophy. In this study the authors assessed the effect of ACE inhibitors on total and cardiovascular mortality in high‐risk AA patients with angiographically proven coronary artery disease (CAD). This was a retrospective analysis of 810 AA men who underwent diagnostic coronary angiography between 1995 and 2003. All patients had demonstrable CAD and had undergone a complete ischemic workup. Follow‐up was from 3 to 10 years. ACE inhibitors were administered to 237 patients, while the remaining 537 patients were not taking ACE inhibitors. Patients taking ACE inhibitors had significantly more comorbidities (hypertension, diabetes, left ventricular hypertrophy, heart failure, severe CAD) at baseline, compared with patients not taking ACE inhibitors (P<.05 for all comorbidities). Despite the unfavorable baseline profile, patients taking ACE inhibitors had significantly lower mortality from CAD during follow‐up than patients who were not taking ACE inhibitors (P=.006). Stroke mortality rates were similar in both groups. Cox regression analysis showed an 80% higher relative risk in patients not receiving ACE inhibitors. These data indicate a substantial benefit from ACE inhibitor therapy in high‐risk AA patients with CAD.
Circulation, Mar 5, 2002
Background-The aim of the present study was to assess the prognostic value of novel repolarizatio... more Background-The aim of the present study was to assess the prognostic value of novel repolarization descriptors from the 12-lead ECG in a large cohort of US veterans. Methods and Results-Male US veterans (nϭ813) with cardiovascular disease had digital 12-lead ECGs recorded at the VA Medical Center, Washington, DC, between 1984 and 1991. The patient series was retrospectively compiled in 1991; follow-up was prospectively assessed until 2000. Novel ECG variables characterizing repolarization and the T-wave loop were automatically analyzed. Of 772 patients with technically analyzable data, 252 patients (32.6%) died after a mean follow-up of 10.4Ϯ3.8 years. Direct comparison between dead and alive patients showed that the so-called T-wave residua (the absolute and relative amount of nondipolar contents within the T wave) predicted mortality (111 900Ϯ164 700 versus 85 600Ϯ144 800 between dead and alive patients, PϽ0.0002; and 0.43Ϯ0.62% versus 0.33Ϯ0.56%, PϽ0.0005 for the absolute and relative T-wave residuum, respectively). On Cox regression analysis entering age, left ventricular ejection fraction, echocardiographic left ventricular hypertrophy, and either of the T-wave residua, risk prediction was independent for the absolute (Pϭ0.022) and for the relative (Pϭ0.006) T-wave residuum, respectively, with age (PϽ0.0001), presence of left ventricular hypertrophy (Pϭ0.002), and left ventricular ejection fraction (Pϭ0.004) also being predictors of survival. Conclusions-The heterogeneity of myocardial repolarization, measured by the so-called T-wave residuum in the ECG, confers long-term independent prognostic information in US veterans with cardiovascular disease. (Circulation. 2002; 105:1066-1070.
Journal of Hypertension, Apr 1, 2021
Journal of the American College of Cardiology, Aug 1, 2022
Journal of the American College of Cardiology, Mar 1, 2023
Journal of Hypertension, 2021
Journal of Hypertension, 2018
Conclusions: The results of the present study demonstrated that 7-days HS diet impairs forearm sk... more Conclusions: The results of the present study demonstrated that 7-days HS diet impairs forearm skin microvascular ACh-induced dilation independently of BP changes in young healthy men, just as we earlier reported in women. Eventhough there are many known sex-related differences in various cardiovascular responses even in healthy individuals, the results of this study suggesst that one week HS loading affects endothelium-dependent vasodilation in peripheral microcirculation correspondingly in young healthy men and women.
Circulation, 2019
Introduction: Left ventricular hypertrophy (LVH) is associated with a significant increase cardio... more Introduction: Left ventricular hypertrophy (LVH) is associated with a significant increase cardiovascular events. LVH is independent of blood pressure (BP) and other confounders. However, the prese...
Journal of Hypertension, Jun 1, 2023
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Papers by Andreas Pittaras