Amudha Kadirvelu

Does one cigarette make an adolescent smoker, and is it influenced by age and age of smoking initiation? Evidence of association from the U.S. Youth Risk Behavior Surveillance System (2011).

OBJECTIVES Evidence that age of smoking initiation represents a risk factor for regular smoking in adolescence is complicated by inconsistencies in the operational definition of smoking initiation and simultaneous inclusion of age as an explanatory variable. The aim of this study was to examine the relationship between age, age of smoking initiation and subsequent regular smoking. METHODS A secondary analysis was conducted of the U.S. Youth Risk Behavior Survey 2011. A sex stratified multivariable logistic regression analysis was used to model the likelihood of regular smoking with age and age of smoking initiation as explanatory variables and race/ethnicity as a covariate. RESULTS After controlling for race/ethnicity, age and age of smoking initiation were independently associated with regular smoking in males and females. Independent of age, a one years decrease in the age of smoking initiation was associated with a 1.27 times increase in odds of regular smoking in females (95% CI: 1.192-1.348); and similar associations for males (OR: 1.28; 95% CI: 1.216-1.341). CONCLUSION While the majority of high school students do not become regular smokers after initiating smoking, earlier initiation of smoking is associated with subsequent regular smoking irrespective of sex or race/ethnicity. These findings have potentially important implications for intervention targeting.

Statins in heart failure: do we need another trial?

Statins lower serum cholesterol and are employed for primary and secondary prevention of cardiovascular events. Clinical evidence from observational studies, retrospective data, and post hoc analyses of data from large statin trials in various cardiovascular conditions, as well as small scale randomized trials, suggest survival and other outcome benefits for heart failure. Two recent large randomized controlled trials, however, appear to suggest statins do not have beneficial effects in heart failure. In addition to lowering cholesterol, statins are believed to have many pleotropic effects which could possibly influence the pathophysiology of heart failure. Following the two large trials, evidence from recent studies appears to support the use of statins in heart failure. This review discusses the role of statins in the pathophysiology of heart failure, current evidence for statin use in heart failure, and suggests directions for future research.

Social support in type II diabetes care: a case of too little, too late

Coping with type II diabetic patients is increasingly posing large financial burdens, sorely felt especially by growing economies. Self-management has been found to be an effective approach towards maintaining good control in diabetics. However, although efforts at implementing self-management have had initial success, there has been a lack of sustainability. This review examines the different components impinging on self-care among type II diabetic patients. These include the critical role of social support, the need for support from health care providers, the value of support from family and friends, the influence of sex and cultural factors in self-care behavior, the benefits of peer support, and the role of literacy in diabetes self-care. Despite the mounting evidence for the effectiveness of social support in diabetes care, and the various stakeholders including this in their clinical guidelines, there has only been a lukewarm response from policy-makers towards ensuring its implementation. Hence, more effort is required from health care providers in moving away from just understanding the effects of new drugs and subsequently putting their patients on these drugs, and going back to the basics of communicating with the patients, understanding their woes, and helping to motivate/empower their patients. This paper analyzes the various components of social support, their influence on diabetes self-care, and how health care providers can help in this process.

Lipophilic versus hydrophilic statin therapy for heart failure: a protocol for an adjusted indirect comparison meta-analysis

AbstractBackgroundStatins are known to reduce cardiovascular morbidity and mortality in primary and secondary prevention studies. Subsequently, a number of nonrandomised studies have shown statins improve clinical outcomes in patients with heart failure (HF). Small randomised controlled trials (RCT) also show improved cardiac function, reduced inflammation and mortality with statins in HF. However, the findings of two large RCTs do not support the evidence provided by previous studies and suggest statins lack beneficial effects in HF. Two meta-analyses have shown statins do not improve survival, whereas two others showed improved cardiac function and reduced inflammation in HF. It appears lipophilic statins produce better survival and other outcome benefits compared to hydrophilic statins. But the two types have not been compared in direct comparison trials in HF.Methods/designWe will conduct a systematic review and meta-analysis of lipophilic and hydrophilic statin therapy in patients with HF. Our objectives are:1.To determine the effects of lipophilic statins on (1) mortality, (2) hospitalisation for worsening HF, (3) cardiac function and (4) inflammation.2.To determine the effects of hydrophilic statins on (1) mortality, (2) hospitalisation for worsening HF, (3) cardiac function and (4) inflammation.3.To compare the efficacy of lipophilic and hydrophilic statins on HF outcomes with an adjusted indirect comparison meta-analysis. We will conduct an electronic search of databases for RCTs that evaluate statins in patients with HF. The reference lists of all identified studies will be reviewed. Two independent reviewers will conduct the search. The inclusion criteria include:1.RCTs comparing statins with placebo or no statin in patients with symptomatic HF.2.RCTs that employed the intention-to-treat (ITT) principle in data analysis.3.Symptomatic HF patients of all aetiologies and on standard treatment.4.Statin of any dose as intervention.5.Placebo or no statin arm as control. The exclusion criteria include:1.RCTs involving cerivastatin in HF patients.2.RCTs with less than 4 weeks of follow-up.DiscussionWe will perform an adjusted indirect comparison meta-analysis of lipophilic versus hydrophilic statins in patients with HF using placebo or no statin arm as common comparator.

Effects of Statin Treatment on Inflammation and Cardiac Function in Heart Failure: An Adjusted Indirect Comparison Meta-Analysis of Randomized Trials.

INTRODUCTION Statins are known to prevent heart failure (HF). However, it is unclear whether statins as class or type (lipophilic or hydrophilic) improve outcomes of established HF. AIMS The current meta-analysis was performed to compare the treatment effects of lipophilic and hydrophilic statins on inflammation and cardiac function in HF. Outcomes were indicators of cardiac function [changes in left ventricular ejection fraction (LVEF) and B-type natriuretic peptide (BNP)] and inflammation [changes in highly sensitive C-reactive protein (hsCRP) and interluekin-6 (IL-6)]. METHOD We conducted a search of PubMed, EMBASE, and the Cochrane databases until December 31, 2014 for randomized control trials (RCTs) of statin versus placebo in patients with HF. RCTs with their respective extracted information were dichotomized into statin type evaluated and analyzed separately. Outcomes were pooled with random effect approach, producing standardized mean differences (SMD) for each statin type. Using these pooled estimates, we performed adjusted indirect comparisons for each outcome. RESULTS Data from 6214 patients from 19 trials were analyzed. Lipophilic statin was superior to hydrophilic statin treatment regarding follow-up LVEF (SMD, 4.54; 95% CI, 4.16-4.91; P < 0.001), BNP (SMD, -1.60; 95% CI, -2.56 to -0.65; P < 0.001), hsCRP (SMD, -1.13; 95% CI, -1.54 to -0.72; P < 0.001), and IL-6 (SMD, -3.75; 95% CI, -4.77 to -0.72; P < 0.001) in HF. CONCLUSIONS Lipophilic statin produces greater treatment effects on cardiac function and inflammation compared with hydrophilic statin in patients with HF. Until data from adequately powered head-to-head trial of the statin types are available, our meta-analysis brings clinicians and researchers a step closer to the quest on which statin--lipophilic or hydrophilic--is associated with better outcomes in HF.

Empathy levels among first year Malaysian medical students: an observational study.

Background The literature indicates that medical practitioners experience declining empathy levels in clinical practice. This highlights the need to educate medical students about empathy as an attribute early in the academic curriculum. The objective of this study was to evaluate year one students’ self-reported empathy levels following a 2-hour empathy workshop at a large medical school in Malaysia. Methods Changes in empathy scores were examined using a paired repeated-measures t-test in this prospective before and after study. Results Analyzing the matched data, there was a statistically significant difference and moderate effect size between mean empathy scores before and 5 weeks after the workshop (112.08±10.67 versus 117.93±13.13, P<0.0001, d=0.48) using the Jefferson Scale Physician Empathy (Student Version). Conclusion The results of this observational study indicate improved mean self-reported empathy scores following an empathy workshop.

Clinical characteristics and prognosis of patients admitted for heart failure: A 5-year retrospective study of African patients

BACKGROUND Mortality associated with heart failure (HF) remains high. There are limited clinical data on mortality among HF patients from African populations. We examined the clinical characteristics, long-term outcomes, and prognostic factors of African HF patients with preserved, mid-range or reduced left ventricular ejection fraction (LVEF). METHODS AND RESULTS We conducted a retrospective longitudinal cohort study of individuals aged ≥18years discharged from first HF admission between January 1, 2009 and December 31, 2013 from the Cardiac Clinic, Directorate of Medicine of the Komfo Anokye Teaching Hospital, Ghana. A total of 1488 patients diagnosed of HF were included in the analysis. Of these, 345 patients (23.2%) had reduced LVEF (LVEF<40%) [HFrEF], 265(17.8%) with mid-range LVEF (40%≥LVEF<50%) [HFmEF] and 878 (59.0%) had preserved LVEF (LVEF≥50%) [HFpEF]. Kaplan-Meier curves and log-rank test demonstrated better prognosis for HFpEF compared to HFrEF and HFmEF patients. An adjusted Cox analysis showed a significantly lower risk of mortality for HFpEF (hazard ratio (HR); 0.74; 95% confidence interval (CI) 0.57-0.94) p=0.015). Multivariate analyses showed that age, higher New York Heart Association (NYHA) functional class, lower LVEF, chronic kidney disease, atrial fibrillation, anemia, diabetes mellitus and absence of statin and aldosterone antagonist treatment were independent predictors of mortality in HF. Although, prognostic factors varied across the three groups, age was a common predictor of mortality in HFpEF and HFmEF. CONCLUSIONS This study identified the clinical characteristics, long-term mortality and prognostic factors of African HF patients with reduced, mid-range and preserved ejection fractions in a clinical setting.

Review of novel therapeutic targets for improving heart failure treatment based on experimental and clinical studies

Heart failure (HF) is a major public health priority due to its epidemiological transition and the world’s aging population. HF is typified by continuous loss of contractile function with reduced, normal, or preserved ejection fraction, elevated vascular resistance, fluid and autonomic imbalance, and ventricular dilatation. Despite considerable advances in the treatment of HF over the past few decades, mortality remains substantial. Pharmacological treatments including β-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and aldosterone antagonists have been proven to prolong the survival of patients with HF. However, there are still instances where patients remain symptomatic, despite optimal use of existing therapeutic agents. This understanding that patients with chronic HF progress into advanced stages despite receiving optimal treatment has increased the quest for alternatives, exploring the roles of additional pathways that contribute to the development and progression of HF. Several pharmacological targets associated with pathogenesis of HF have been identified and novel therapies have emerged. In this work, we review recent evidence from proposed mechanisms to the outcomes of experimental and clinical studies of the novel pharmacological agents that have emerged for the treatment of HF.

Statin Treatment and Clinical Outcomes of Heart Failure Among Africans: An Inverse Probability Treatment Weighted Analysis

Background Randomized control trials of statins have not demonstrated significant benefits in outcomes of heart failure (HF). However, randomized control trials may not always be generalizable. The aim was to determine whether statin and statin type–lipophilic or –hydrophilic improve long‐term outcomes in Africans with HF. Methods and Results This was a retrospective longitudinal study of HF patients aged ≥18 years hospitalized at a tertiary healthcare center between January 1, 2009 and December 31, 2013 in Ghana. Patients were eligible if they were discharged from first admission for HF (index admission) and followed up to time of all‐cause, cardiovascular, and HF mortality or end of study. Multivariable time‐dependent Cox model and inverse‐probability‐of‐treatment weighting of marginal structural model were used to estimate associations between statin treatment and outcomes. Adjusted hazard ratios were also estimated for lipophilic and hydrophilic statin compared with no statin use. The study included 1488 patients (mean age 60.3±14.2 years) with 9306 person‐years of observation. Using the time‐dependent Cox model, the 5‐year adjusted hazard ratios with 95% CI for statin treatment on all‐cause, cardiovascular, and HF mortality were 0.68 (0.55–0.83), 0.67 (0.54–0.82), and 0.63 (0.51–0.79), respectively. Use of inverse‐probability‐of‐treatment weighting resulted in estimates of 0.79 (0.65–0.96), 0.77 (0.63–0.96), and 0.77 (0.61–0.95) for statin treatment on all‐cause, cardiovascular, and HF mortality, respectively, compared with no statin use. Conclusions Among Africans with HF, statin treatment was associated with significant reduction in mortality.

Fuzzy clustering in digital mammograms using Gray Level co-occurrence matrices

Digital mammograms are difficult images to interpret. Data clustering plays a very crucial role in automatic detection of clustered calcifications in digital mammograms. The aim of this paper is to review and compare the performance of the three main data clustering techniques namely K-means clustering, Fuzzy C-Means clustering and Subtractive clustering. The digital mammograms for the study are taken from Mammographie Image Analysis Society (MIAS) digital mammogram database. The contrast limited adaptive histogram equalization (CLAHE) method is used to reduce noise in digital mammograms. The Gray Level co-occurrence Matrices (GLCM) for different distances and angles are constructed. The performance results of the clustering techniques based on mean square errors are tabulated and compared. It was found that the Subtractive clustering technique outperforms the other two techniques.