The impact of unsuccessful percutaneous coronary intervention on short‐ and long‐term prognosis in STEMI and NSTEMI

OBJECTIVES: To compare the impact of the efficacy of percutaneous coronary intervention (PCI) on prognosis in ST and non-ST elevation myocardial infarction (STEMI and NSTEMI) patients with respect to infarct-related artery (IRA). BACKGROUND: The significance of the efficacy of PCI in STEMI and NSTEMI depending on the type of IRA has yet to be clarified. METHODS: Study population consisted of 2,179 STEMI and 554 NSTEMI consecutive patients treated with urgent PCI. The efficacy of PCI (TIMI [thrombolysis in myocardial infarction] 3 vs. TIMI < 3) was assessed with regard to the type of IRA (left anterior descending artery, circumflex artery [Cx] or right coronary artery). The mean follow-up was 37.5 months. RESULTS: The rate of unsuccessful PCI was similar in STEMI and NSTEMI irrespectively of IRA (14.1 vs. 17.7%; P = 0.062). In STEMI, unsuccessful PCI was associated with significantly higher early (23.1 vs. 5.6%; P < 0.001) and late (29.9 vs. 12.8%; P < 0.001) mortality regardless of IRA. In NSTEMI, the inefficacious PCI significantly increased early (19.0% vs. 0.9%; P < 0.001) and late (27.3% vs. 6.3%; P < 0.001) mortality only in patients with Cx-related infarction. Unsuccessful PCI of IRA was an independent risk factor for death in STEMI (HR 1.64; P < 0.05), but not in NSTEMI (P = 0.64). Further analysis showed that whilst unsuccessful PCI of any vessel in STEMI is an independent risk factor for death, in NSTEMI this applies to unsuccessful PCI of Cx only. CONCLUSIONS: The significance of unsuccessful PCI of IRA seems to be different in STEMI and NSTEMI. Unsuccessful PCI is an independent risk factor for death in STEMI regardless of IRA and in NSTEMI with the involvement of Cx.