Azhar Supariwala

Quantification of left ventricular remodeling in response to isolated aortic or mitral regurgitation

BackgroundThe treatment of patients with aortic regurgitation (AR) or mitral regurgitation (MR) relies on the accurate assessment of the severity of the regurgitation as well as its effect on left ventricular (LV) size and function. Cardiovascular Magnetic Resonance (CMR) is an excellent tool for quantifying regurgitant volumes as well as LV size and function. The 2008 AHA/ACC management guidelines for the therapy of patients with AR or MR only describe LV size in terms of linear dimensions (i.e. end-diastolic and end-systolic dimension). LV volumes that correspond to these linear dimensions have not been published in the peer-reviewed literature. The purpose of this study is to determine the effect of regurgitant volume on LV volumes and chamber dimensions in patients with isolated AR or MR and preserved LV function.MethodsRegurgitant volume, LV volume, mass, linear dimensions, and ejection fraction, were determined in 34 consecutive patients with isolated AR and 23 consecutive patients with MR and no other known cardiac disease.ResultsThere is a strong, linear relationship between regurgitant volume and LV end-diastolic volume index (aortic regurgitation r2 = 0.8, mitral regurgitation r2 = 0.8). Bland-Altman analysis of regurgitant volume shows little interobserver variation (AR: 0.6 ± 4 ml; MR 4 ± 6 ml). The correlation is much poorer between regurgitant volume and commonly used clinical linear measures such as end-systolic dimension (mitral regurgitation r2 = 0.3, aortic regurgitation r2 = 0.5). For a given regurgitant volume, AR causes greater LV enlargement and hypertrophy than MR.ConclusionCMR is an accurate and robust technique for quantifying regurgitant volume in patients with AR or MR. Ventricular volumes show a stronger correlation with regurgitant volume than linear dimensions, suggesting LV volumes better reflect ventricular remodeling in patients with isolated mitral or aortic regurgitation. Ventricular volumes that correspond to published recommended linear dimensions are determined to guide the timing of surgical intervention.

Appropriateness of Statins in Patients Aged ≥80 Years and Comparison to Other Age Groups

In patients aged ≥80 years without previous coronary artery disease, peripheral vascular disease, or cerebrovascular disease, no evidence has shown a benefit from statin therapy. We examined the prevalence of statin use in patients aged ≥80 years for the indication of primary prevention. We reviewed the comprehensive electronic health records at the Geisinger Health System in Pennsylvania for all patients aged >55 years with ≥1 primary care encounter from January 24, 2004 and December 31, 2009. The records were scrutinized for the use of a statin, active medical diagnoses, and laboratory values. Patients without a previous diagnosis of coronary artery disease, peripheral vascular disease, or cerebrovascular disease were considered to have a primary prevention indication for statin therapy. The prevalence of statin use was examined, and a multivariate analysis was conducted to determine the predictors of use. A total of 89,086 patients were included in the analysis, with 22,646 patients aged ≥80 years. Of all the patients, 26% were prescribed a statin, of whom, 71% (n = 16,687) received it for primary prevention. Of the 14,604 patients aged ≥80 years with a primary prevention indication, 3,145 (22%) received a statin. A plot of 5-year age cohorts from 55 to >90 years demonstrated an n-shaped relation between age and statin use for primary prevention (18%, 23%, 27%, 29%, 28%, 26%, 21%, and 12%, p <0.001). Compared to patients aged <65 years, the ratio of statin prescription for secondary to primary prevention was 31% lower in patients aged ≥80 years (1.3 vs 1.9). Those aged ≥80 years with a primary prevention indication had, with treatment, a mean low-density lipoprotein level of 84 ± 26 mg/dl. In conclusion, many patients aged ≥80 years receive statin therapy for primary prevention and are treated to aggressive low-density lipoprotein levels. Because the efficacy is uncertain and the potential adverse effects are many, we urgently need to define the cost, benefit, and risk of statin use in the very elderly.

The interaction of exercise ability and body mass index upon long-term outcomes among patients undergoing stress-rest perfusion single-photon emission computed tomography imaging

BACKGROUND The obesity paradox has been reported in several populations of patients with cardiovascular disease. Recent data have shown that physical fitness may attenuate the obesity paradox. Patients who undergo pharmacologic stress testing are known to have a higher risk of mortality than those who can exercise. The purpose of this study is to determine the interaction of obesity and exercise ability on survival among patients with a normal stress-rest single-photon emission computed tomography (SPECT). METHODS A total of 5,203 (60 ± 13 years, male 37%) patients without a history of heart disease and a normal stress-rest SPECT between the years 1995 and 2010 were included in this analysis. Body mass index categories were defined according to the World Health Organization classification: normal weight, 18.5 to 24.9 kg/m(2); overweight, 25 to 29.9 kg/m(2); and obese, ≥30 kg/m(2). Patients were divided into 3 groups based on their ability to exercise: those who reached ≥6 METs on exercise, those who attained a level of <6 METs, and those who required pharmacologic stress. Patients in each of these fitness groups were further divided into 3 subgroups based on their body mass index. RESULTS There were 939 (18%) deaths during a mean follow-up of 8.1 ± 4.1 years, for an overall event rate of 2.3%/y. Both exercise to ≥6 METs and being obese were associated with lower mortality. Adjusted multivariate analysis using the obese high-fit patients as the reference showed a wide heterogeneity in annualized mortality rates according to exercise and weight status, with annualized event rates which varied from 0.6%/y in the obese subjects who were physically fit to 5.3%/y among healthy subjects who underwent pharmacologic stress testing (P < .001). CONCLUSIONS Stress mode and body weight impacted long-term survival in patients with a normal stress SPECT. The benefit of being physically fit was evident in all weight groups, as was the adverse effect of being unable to exercise. However, with regard to body weight, there was a paradoxical survival advantage for those patients who were overweight and obese, regardless of their exercise ability.

Antihypertensive efficacy of angiotensin receptor blockers as monotherapy as evaluated by ambulatory blood pressure monitoring: a meta-analysis

AIMS Angiotensin receptor blockers (ARBs) are available in different dosages and it is common clinical practice to uptitrate if blood pressure goal is not achieved with the initial dose. Data on the incremental antihypertensive efficacy with uptitration are scarce. It is also unclear if antihypertensive efficacy of losartan is comparable with other ARBs. METHODS AND RESULTS We systematically reviewed PubMed/EMBASE/Cochrane databases for all randomized clinical trials until December 2012 reporting 24 h ambulatory blood pressure (ABP) for most commonly available ARBs in patients with hypertension. Reduction in ABP with ARBs was evaluated at 25% of the maximum (max) dose, 50% of the max dose, and at the max dose. Comparison was made between 24 h BP-lowering effect of losartan 50 and 100 mg and other ARBs at 50% max dose and the max dose, respectively. Sixty-two studies enrolling 15 289 patients (mean age 56 years; 60% men) with a mean duration of 10 weeks were included in the analysis. Overall, the dose-response curve with ARBs was shallow with decrease of 10.3/6.7 (systolic/diastolic), 11.7/7.6, and 13.0/8.3 mmHg with 25% max dose, 50% max dose, and with the max dose of ARBs, respectively. Losartan in the dose of 50 mg lowered ABP less well than other ARBs at 50% max dose by 2.5 mmHg systolic (P < 0.0001) and 1.8 mmHg diastolic (P = 0.0003). Losartan 100 mg lowered ABP less well than other ARBs at max dose by 3.9 mm Hg systolic (P = 0.0002) and 2.2 mmHg diastolic (P = 0.002). CONCLUSION In this comprehensive analysis of the antihypertensive efficacy of ARBs by 24 h ABP, we observed a shallow dose-response curve, and uptitration marginally enhanced the antihypertensive efficacy. Blood pressure reduction with losartan at starting dose and at max dose was consistently inferior to the other ARBs.

Clinical outcomes following a strategy of optimized medical management and selective “downstream” procedures following coronary computed tomography angiography

BACKGROUND Prior studies have shown a consistent relationship between coronary artery calcium (CAC) scores or the degree of coronary stenoses on coronary computed tomography angiography (CCTA) and all-cause mortality. Whether CCTA-targeted therapy, including intensive medical management, stress testing and/or invasive coronary angiography (ICA), can lead to a substantial reduction in adverse outcomes is not yet known. METHODS We retrospectively analyzed 691 patients (55±13 years, male=63%) from a single medical practice who underwent a CAC scan and CCTA and were followed for a mean of 2.9±1.0 years. Of these, 416 (60%) patients were asymptomatic. All changes in medications, coronary risk factors (including lipids profiles), downstream testing, revascularization procedures, and clinical events (myocardial infarction and death) were recorded. RESULTS Among our patients cohort 279 (40%) had no coronary artery disease. The most severe stenosis was <50% in 314 (46%) patients, 50-70% in 76 (11%) patients, and >70% in 22 (3%) patients. A high frequency of medical therapy was employed for those patients with any degree of stenosis, while stress testing was primarily applied for patients with >50% stenosis and ICA was primarily performed in those with >70% stenosis. Only two non-cardiovascular deaths and no cardiovascular deaths occurred during the follow-up period. CONCLUSIONS Our findings support the hypotheses that among patients undergoing CCTA, comprehensive medical management, including targeted percutaneous coronary interventions and increasingly intensive medical therapy with progressively worse CCTA findings, can reduce event rates among patients with abnormal CCTA studies.

Influence of Mode of Stress and Coronary Risk Factor Burden Upon Long-Term Mortality Following Normal Stress Myocardial Perfusion Single-Photon Emission Computed Tomographic Imaging

In patients with normal results on stress single-photon emission computed tomographic (SPECT) studies, coronary artery disease risk factors (RFs) and the mode of testing can influence the trajectory of long-term outcomes. Nevertheless, the combined prognostic impact of these commonly assessed factors has heretofore not been considered. In this study, all-cause mortality rates were assessed in 5,762 patients with normal results on stress SPECT studies. Patients were divided according to mode of stress testing, exercise or pharmacologic, and by number of coronary artery disease RFs. Patients were followed for a mean of 8 ± 4.2 years for all-cause mortality. There were 1,051 deaths (18%), with an annualized mortality rate of 2.2% per year. The RF-adjusted event rate was significantly higher for pharmacologic versus exercise SPECT studies (3.6% per year vs 1.2% per year, p <0.0001) and for patients with increasing numbers of coronary artery disease RFs (p <0.0001). Kaplan-Meier survival analysis revealed wide heterogeneity in all-cause mortality rates when RF burden and performance of exercise versus pharmacologic testing were considered, ranging from only 0.8% per year in exercise patients with no RFs to 4.2% per year in pharmacologic patients with ≥2 RFs. Mortality rates in exercise patients with ≥2 RFs were comparable to those in pharmacologic patients with no RFs. In conclusion, long-term outcomes after cardiac stress testing are synergistically and strongly influenced by RF burden and inability to exercise. Given these findings, prospective study is indicated to determine whether enhanced risk categorization that combines the consideration of these 2 factors improves patient counseling and physician risk management among patients manifesting normal results on stress SPECT studies.

Feasibility and Prognostic Value of Stress Echocardiography in Obese, Morbidly Obese, and Super Obese Patients Referred for Bariatric Surgery

Stress echocardiography (SE) is clinically used in the risk stratification and prognosis of patients with coronary artery disease. Due to multiple comorbidities, obese patients have increased risk of adverse cardiovascular events perioperatively in noncardiac surgery. The aim of this study was to investigate the feasibility of SE in morbidly obese patients undergoing bariatric surgery.

Cardiac Magnetic Resonance Evaluation of the Impact of Interventricular and Intraventricular Dyssynchrony on Cardiac Ventricular Systolic and Diastolic Function in Patients With Isolated Left Bundle Branch Block

Ventricular dyssynchrony significantly impairs cardiac performance. However, the independent role of interventricular dyssynchrony (interVD) and intraventricular dyssynchrony (intraVD) in the development of abnormalities of systolic and diastolic performance is unclear. Cardiac magnetic resonance imaging was performed in 39 patients with left bundle branch block and 13 healthy patients. Structural and functional parameters of the left ventricle and degrees of interVD and intraVD were measured. We found that interVD was inversely correlated with left ventricular (LV) ejection fraction (r = -0.8, p <0.0001) and positively correlated with LV end-diastolic volume (r = 0.4, p <0.01), LV end-systolic volume (r = 0.6, p <0.0001), and LV mass (r = 0.4, p <0.01), thus indicating that interVD significantly affects systolic function and favors ventricular remodeling. Multivariate analysis further confirmed that interVD was an independent predictor of systolic dysfunction. Interestingly, we found that interVD was not associated with abnormalities of diastolic performance. Conversely, we found that intraVD significantly impaired diastolic function, whereas it had no effect on systolic function. IntraVD was inversely correlated with peak filling rate (r = -0.7, p <0.0001) and 1/2 filling fraction (r = 0.4, p = 0.04) and positively correlated with time to peak filling rate (r = 0.6, p <0.0001), validated parameters of diastolic function. Multivariate analysis confirmed that intraVD was an independent predictor of diastolic dysfunction. In conclusion, our study suggests that the 2 components of ventricular dyssynchrony differently affect cardiac performance. If confirmed in prospective studies, our results may help to predict the prognosis of patients with left bundle branch block and different degrees of interVD and intraVD, particularly those subjects undergoing cardiac resynchronization therapy.

A novel technique to quantify the instantaneous mitral regurgitant rate

BackgroundThe systolic variation of mitral regurgitation (MR) is a pitfall in its quantification. Current recommendations advocate using quantitative echocardiographic techniques that account for this systolic variation. While prior studies have qualitatively described patterns of systolic variation no study has quantified this variation.MethodsThis study includes 41 patients who underwent cardiovascular magnetic resonance (CMR) evaluation for the assessment of MR. Systole was divided into 3 equal parts: early, mid, and late. The MR jets were categorized as holosystolc, early, or late based on the portions of systole the jet was visible. The aortic flow and left ventricular stroke volume (LVSV) acquired by CMR were plotted against time. The instantaneous regurgitant rate was calculated for each third of systole as the difference between the LVSV and the aortic flow.ResultsThe regurgitant rate varied widely with a 1.9-fold, 3.4-fold, and 1.6-fold difference between the lowest and highest rate in patients with early, late, and holosystolic jets respectively. There was overlap of peak regurgitant rates among patients with mild, moderate and severe MR. The greatest variation of regurgitant rate was seen among patients with mild MR.ConclusionCMR can quantify the systolic temporal variation of MR. There is significant variation of the mitral regurgitant rate even among patients with holosystolic MR jets. These findings highlight the need to use quantitative measures of MR severity that take into consideration the temporal variation of MR.

Improvement in Physical Activity in Persons With Obstructive Sleep Apnea Treated With Continuous Positive Airway Pressure

BACKGROUND Exercise improves sleep quality, yet people with untreated obstructive sleep apnea (OSA) may engage in less physical activity (PA) due to fatigue and daytime sleepiness. We examined changes in PA and sleep quality before and after treatment with continuous positive airway pressure (CPAP) in OSA patients. METHODS In this prospective longitudinal study, persons with a primary diagnosis of OSA were enrolled at a community-based hospital in New York City. At 3 time intervals pre- and post-CPAP (3-8 months), we measured sleep quality using validated questionnaires, perceived PA using the International Physical Activity Questionnaire (IPAQ), and actual PA using pedometer steps per day. We sought to investigate how CPAP use and changes in sleep quality impacted the number of steps taken, as recorded in pedometer steps. RESULTS In total, 62 patients were enrolled in the study from March 2012 to July 2014. In all, patients averaged 53 years of age, and 26 patients (42%) were female. Among all participants, 86% of persons had moderate to severe sleep apnea (AHI ≥15). Approximately 73% of participants were compliant with CPAP use. Poor sleep quality correlated with lower actual PA (P = .004) at baseline. At 3 and 7 months, there was significant improvement in sleep quality (Δ -2.63 ± 3.4 and Δ -3.5 ± 3.8; P < .001) and actual PA (Δ 840 ± 1313 and Δ 1431 ± 1419 steps/day, P < .001) compared with baseline. On multivariate analyses, participants with a higher waist circumference had a significantly greater increase in actual PA (P = .018). CONCLUSION Treatment of OSA with CPAP had a progressive incremental improvement in sleep quality and actual PA.