Adjunctive qiliqiangxin capsule for heart failure in predominantly middle-aged and older adults: a systematic review and meta-analysis of randomized controlled trials

Background: Heart failure (HF) is highly prevalent among middle-aged and older adults and remains associated with substantial residual morbidity and mortality despite guideline-guided treatment. Previous meta-analyses of Qiliqiangxin Capsule (QLQX) have mainly focused on general HF populations or patients with HF with reduced ejection fraction (HFrEF), with limited attention to age-related clinical applicability. Therefore, this study evaluated the adjunctive effects of QLQX in predominantly middle-aged and older study populations with HF. Objective: To evaluate the efficacy of QLQX combined with conventional therapies (CTs) on cardiac function in middle-aged and older HF patients. Methods: Seven databases were searched from inception to January 2026 for RCTs of QLQX. Two reviewers independently screened studies and extracted data. The risk of bias and the certainty of the evidence were assessed using the Cochrane risk-of-bias tool and GRADE. Meta-analysis used random-effects models for continuous outcomes and fixed-effects models for dichotomous outcomes when heterogeneity was low. Subgroup and sensitivity analyses explored heterogeneity and tested robustness. Results: Eleven RCTs involving 4,642 participants were included. Compared with CTs alone or placebo plus CTs, QLQX combined with CTs was associated with higher LVEF across 10 trials involving 1,532 participants [MD = 5.77, 95% CI (4.32, 7.22)] and lower NT-proBNP levels [MD = -312.98 pg/mL, 95% CI (-418.31, -207.64)]. The pooled estimate also favored QLQX for LVEDD [MD = -3.50, 95% CI (-4.65, -2.35)]. HF hospitalization or rehospitalization was reported in two trials, and the pooled cumulative risk estimate favored QLQX [RR = 0.80, 95% CI (0.69, 0.93)]. However, these findings should be interpreted with caution because substantial heterogeneity was observed across several outcomes, follow-up durations varied across studies, and evidence for hard clinical endpoints remained limited, with outcome-specific certainty ranging from moderate to very low. Conclusion: QLQX combined with CTs may be associated with short- to medium-term improvements in surrogate measures of cardiac function and functional status in predominantly middle-aged and older study populations with HF. However, evidence regarding hard clinical endpoints remains limited, and large-scale, multicenter, high-quality, double-blind RCTs are needed to clarify its long-term efficacy and prognostic value. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD420261295659, identifier CRD420261295659.