Effect of diltiazem sustained-release capsules on cardiorenal composite outcomes in hypertensive patients with coronary heart disease: A real-world propensity score-matched study

Background: Hypertension frequently coexists with coronary heart disease (CHD) and integrated management is essential to reduce cardiovascular and renal complications. Objectives: To evaluate the efficacy and safety of add-on sustained-release diltiazem capsules in patients with hypertension and CHD. Methods: This retrospective cohort analysis included 302 consecutive patients with CHD treated at the Affiliated Hospital of Jiangnan University between May 2021 and May 2024. Patients were divided into a control group (n=158) receiving standard guideline-directed therapy and a diltiazem group (n=144) receiving add-on diltiazem sustained-release capsules. Propensity scores were used to match and balance baseline covariates to reduce selection bias. Following matching, intergroup comparisons for baseline characteristics, occurrence of cardiorenal composite endpoints, blood pressure, heart rate (HR) control during follow-up and adverse drug reactions were conducted. Multivariate regression analysis was used to determine predictors of cardiorenal endpoint events. Results: After matching, baseline covariates were well-balanced between groups. During a median follow-up of 18 months, the cumulative incidence of cardiorenal composite endpoint events was lower in the diltiazem group than in controls (16.39% vs. 32.79%, P=0.002). Multivariate Cox analysis showed that diltiazem therapy was independently associated with a lower risk of composite outcomes (hazard ratio = 0.465, 95% CI: 0.284–0.760, P = 0.002). Patients receiving diltiazem also had a lower mean HR and higher achievement rates for HR control and combined blood pressure/HR targets (all P<0.05). The reduction in composite outcomes was primarily driven by fewer heart failure rehospitalizations. Drug-related adverse events were comparable between groups. Conclusion: Adding sustained-release diltiazem capsules to standard therapy is associated with a lower cardiorenal composite endpoint risk in patients with hypertension and CHD. The observed benefit was mainly driven by fewer heart failure rehospitalizations, alongwith improved control of blood pressure and heart rate. The renal findings should be considered exploratory because the number of renal events was limited.