The Burden of Cardiovascular Disease in Low- and Middle-Income Countries: Epidemiology and Management.

Cardiovascular disease (CVD) is the second leading cause of mortality worldwide, accounting for 17 million deaths in 2013. More than 80% of these cases were in low- and middle-income countries (LMICs). Although the risk factors for the development of CVD are similar throughout the world, the evolving change in lifestyle and health behaviours in LMICs-including tobacco use, decreased physical activity, and obesity-are contributing to the escalating presence of CVD and mortality. Although CVD mortality is falling in high-income settings because of more effective preventive and management programs, access to evidence-based interventions for combating CVD in resource-limited settings is variable. The existing pressures on both human and financial resources impact the efforts of controlling CVD. The implementation of emerging innovative interventions to improve medication adherence, introducing m-health programs, and decentralizing the management of chronic diseases are promising methods to reduce the burden of chronic disease management on such fragile health care systems.

Gender and racial disparities in adherence to statin therapy: a meta-analysis.

BACKGROUND: Significant disparities exist in cardiovascular outcomes based on race/ethnicity and gender. Rates of evidence-based medication use and long-term medication adherence also appear to be lower in racial subgroups and women but have been subject to little attention. Our objective was to evaluate the effect of race/ethnicity and gender on adherence to statin therapy for primary or secondary prevention. METHODS AND RESULTS: Studies were identified through a systematic search of MEDLINE, EMBASE, ClinicalTrials.gov, and the Cochrane Database of Systematic Reviews (through April 1, 2010) and manual examination of references in selected articles. Studies reporting on adherence to statins by men and women or patients of white and nonwhite race were included. Information on study design, adherence measurement, duration, geographic location, sample size, and patient demographics was extracted using a standardized protocol. From 3,022 potentially relevant publications, 53 studies were included. Compared with men, women had a 10% greater odds of nonadherence (odds ratio 1.10, 95% confidence interval [CI], 1.07-1.13). Nonwhite race patients had a 53% greater odds of nonadherence than white race patients (odds ratio 1.53, 95% CI 1.25-1.87). There was significant heterogeneity in the pooled estimate for gender (I(2) 0.95, P value for heterogeneity <.001) and race (I(2) 0.98, P value for heterogeneity <.001). The overall results remained unchanged in those subgroups that had significantly less heterogeneity. CONCLUSIONS: Among patients prescribed statins, women and nonwhite patients are at increased risk for nonadherence. Further research is needed to identify interventions best suited to improve adherence in these populations.

A systematic review of adherence to cardiovascular medications in resource-limited settings.

BACKGROUND: Medications are a cornerstone of the prevention and management of cardiovascular disease. Long-term medication adherence has been the subject of increasing attention in the developed world but has received little attention in resource-limited settings, where the burden of disease is particularly high and growing rapidly. To evaluate prevalence and predictors of non-adherence to cardiovascular medications in this context, we systematically reviewed the peer-reviewed literature. METHODS: We performed an electronic search of Ovid Medline, Embase and International Pharmaceutical Abstracts from 1966 to August 2010 for studies that measured adherence to cardiovascular medications in the developing world. A DerSimonian-Laird random effects method was used to pool the adherence estimates across studies. Between-study heterogeneity was estimated with an I(2) statistic and studies were stratified by disease group and the method by which adherence was assessed. Predictors of non-adherence were also examined. FINDINGS: Our search identified 2,353 abstracts, of which 76 studies met our inclusion criteria. Overall adherence was 57.5% (95% confidence interval [CI] 52.3% to 62.7%; I(2) 0.98) and was consistent across study subgroups. Studies that assessed adherence with pill counts reported higher levels of adherence (62.1%, 95% CI 49.7% to 73.8%; I(2) 0.83) than those using self-report (54.6%, 95% CI 47.7% to 61.5%; I(2) 0.93). Adherence did not vary by geographic region, urban vs. rural settings, or the complexity of a patient's medication regimen. The most common predictors of poor adherence included poor knowledge, negative perceptions about medication, side effects and high medication costs. INTERPRETATION: Our study indicates that adherence to cardiovascular medication in resource-limited countries is sub-optimal and appears very similar to that observed in resource-rich countries. Efforts to improve adherence in resource-limited settings should be a priority given the burden of heart disease in this context, the central role of medications in their management, and the clinical and economic consequences of non-adherence.

Meta-analysis of the efficacy and safety of clopidogrel plus aspirin as compared to antiplatelet monotherapy for the prevention of vascular events.

Antiplatelet agents are central to the treatment and prevention of cardiovascular disease. Although aspirin is the most widely used agent, randomized trials have assessed whether adding clopidogrel to aspirin ("dual-antiplatelet therapy") offers additional benefit with acceptable safety. Unfortunately, these trials have reached conflicting results, in part because of the heterogenous populations they studied. To clarify the role of dual-antiplatelet therapy for patients with vascular disease, a systematic review and meta-analysis of randomized controlled trials was performed. Medline and the Cochrane Collaboration and American College of Physicians Journal Club databases were searched for trials published from 1966 to August 2006 that compared aspirin and clopidogrel with antiplatelet monotherapy. Only trials that presented clinically relevant efficacy and safety outcomes were included. From each trial, demographic data and outcomes were recorded. Summary odds ratios and 95% confidence intervals (CIs) were calculated using a random-effects model. Eight trials comprising 91,744 patients were included. Mean follow-up ranged from 28 days to 18 months. Compared with aspirin alone, dual therapy with aspirin and clopidogrel reduced the odds ratio of the composite outcome of death, reinfarction, and stroke by 15% (95% CI 23% to 6%) in patients with acute coronary syndromes and by 34% (95% CI 44% to 22%) in patients who underwent percutaneous coronary intervention. Dual therapy also significantly reduced the odds of fatal and nonfatal reinfarction in these patient groups but did not significantly reduce the odds of all-cause mortality. Dual therapy was associated with significantly increased risk for major bleeding in studies >1 month in duration (odds ratio 1.80, 95% CI 1.40 to 2.30). In conclusion, combining aspirin and clopidogrel significantly reduces the odds of major cardiovascular events in patients with acute coronary syndromes or those who undergo percutaneous coronary intervention but at the expense of significant increases in the risk for bleeding.