Clinical Benefits and Harms of Diuretics for Primary Prevention of Cardiovascular Outcomes in Black People With Essential Hypertension: A Protocol for a Systematic Review of Randomized Clinical Trials With Meta-analysis and Trial Sequential Analysis

Abstract Background The overall mortality attributable to cardiovascular diseases (coronary heart disease, sudden cardiac death/sudden cardiac arrest, stroke/transient ischemic attack, and peripheral arterial disease) is higher in the Black population when compared to the White population. Essential hypertension (EH) is the most important modifiable risk factor for cardiovascular diseases. The prevalence of hypertension among Black adults is also higher. Diuretics are antihypertensive drugs, and their role in the primary prevention of clinical cardiovascular outcomes in the Black population with essential hypertension remains unknown. To assess the clinical benefits and harms of diuretics, as a primary prevention approach, compared with placebo or any other antihypertensive medications.MethodsWe will search the Cochrane Central Register of Controlled Trials (to update), OVID MEDLINE (1946 to update), Embase (1980 to update), LILACS (1986 to update), and Web of Science (to update). We will manually search the reference lists of the included papers and contact researchers in the field. There will be no language restrictions in the search. We will include parallel-design and crossover randomized clinical trials that has adult Black people with essential hypertension as the population. The primary outcomes are all-cause mortality, myocardial infarction, stroke, and serious adverse events. Pregnant women will be excluded from the study. We will perform study selection, risk of bias assessment, and data extraction in duplicate. We will estimate risk ratios (RRs) with a 95% confidence interval (95% CI) for dichotomous outcomes. For continuous outcomes, such as health-related quality of life, systolic blood pressure, and diastolic blood pressure, we will calculate the mean difference with 95% CI or the standardized mean difference with 95% CI. We will measure statistical heterogeneity using the I² statistic and use a fixed-effects and random-effects model. We will conduct a sequential trial analysis. DiscussionOur aim is to provide external validity and try to solve conflicts about the evidence regarding use of diuretics as a primary prevention of cardiovascular outcomes in Black people with essential hypertension to guide appropriate clinical practice.Systematic review registration PROSPERO registration number: CRD42021240864