This study aimed to evaluate the effect of trimetazidine (TMZ) in addition to standard treatment on exercise tolerance in patients with ischemic heart disease (IHD).

Studies were identified via a systematic search of PubMed, Embase, Cochrane Library, and the Chinese CNKI databases from January 1978 to January 2015. Data extraction, synthesis, and statistical analysis were performed by standard meta-analysis methods. Random or fixed effects models were used to estimate pooled mean differences in total exercise duration (TED), peak oxygen uptake (pVO₂), metabolic equivalent system (METS), and 6-minute walking test (6-MWT).

In all, 16 randomized controlled trials (RCTs) consisting of 2,004 participants were included. Pooled results showed that TMZ treatment significantly improved TED (WMD: 37.35, 95 % CI: 25.58–49.13, p < 0.00001), pVO₂ (WMD: 2.41, 95 % CI: 1.76–3.06, p < 0.00001), METS (WMD: 1.33, 95 % CI: 0.38–2.28, p = 0.006), and 6-WMT (WMD: 62.46, 95 % CI: 35.86–89.05, p < 0.001) in all patients with IHD. Subgroup analysis showed that TMZ significantly increased TED in nondiabetic participants (WMD 34.77, 95 % CI: 22.28–47.25, p < 0.001), but not in diabetic participants (WMD: 40.36, 95 % CI: − 18.76–99.48, p = 0.18). And, subgroup analysis of TED by intervention duration suggested that there is no statistically difference between the 3-month and 6-month periods (WMD: 35.47, 95 %CI: 18.35–52.60, p < 0.0001 and WMD: 49.94, 95 %CI: 44.69–55.19, p < 0.00001). In addition, TMZ improved TED (WMD: 50.01, 95 % CI: 44.77–55.25 and WMD: 24.20, 95 % CI: 12.72–35.68) in IHD patients with or without heart failure (HF), respectively.

Addition of TMZ to standard treatment significantly improved exercise tolerance in patients with IHD, and IHD patients with HF may experience even more benefits. However, there is insufficient evidence to show that TMZ has beneficial effects in participants with diabetes.