ObjectiveTo evaluate the effect of SGLT2is, pioglitazone, and their combination on the risk of major adverse cardiovascular events (MACE) and heart failure in type 2 diabetes mellitus (T2DM) patients without a history of cardiovascular disease. Research design and methodsUsing Taiwan National Health Insurance Research Database, we identified four groups based on medication use, including 1) both SGLT2is and pioglitazone, 2) SGLT2i, 3) pioglitazone and 4) non-study drugs (reference group). The four groups were matched by propensity score. The primary outcome was 3-point MACE, which included myocardial infarction, stroke, cardiovascular death, and the secondary outcome was incidence of heart failure. ResultsAfter propensity-matching, each group included 15,601 patients. Compared with the reference group, the pioglitazone/SGLT2i combination group had a significantly lower risk for MACE (aHR 0.76, 95 % CI 0.66–0.88) and heart failure (aHR 0.67, 95 % CI 0.55–0.82). Pioglitazone was associated with a lower risk of MACE (aHR 0.82, 95 % CI 0.71–0.94) and there was no difference in risk of heart failure compared with the reference group. The incidence of heart failure was significantly decreased in the SGLT2i group (aHR 0.7, 95 % CI 0.58–0.86). ConclusionCombination therapy with pioglitazone and SGLT2is is an effective treatment in the primary prevention of MACE and heart failure in patients with type 2 diabetes.