The impact of no-reflow phenomena after primary percutaneous coronary intervention: A time-dependent analysis of mortality

BACKGROUND: The no-reflow phenomenon is a potential complication of primary percutaneous coronary intervention (PCI). Predictors of the no-reflow phenomenon and the impact on long-term mortality remain unclear. METHODS: Two thousand and seventeen patients with ST-segment elevation myocardial infarction (STEMI) who had undergone primary PCI were consecutively enrolled in the multicentre Acute Myocardial Infarction registry of Korea. The no-reflow phenomenon was diagnosed on the basis of angiographic criteria. The primary outcome was all-cause mortality. RESULTS: The no-reflow phenomenon was diagnosed in 262 patients (13.0%). Independent predictors of no-reflow were older age, high Killip class, reduced pre-PCI thrombolysis in myocardial infarction flow grade, and longer stent length in the culprit vessel. During a median follow-up period of 4.1 years (interquartile range: 3.0-5.2 years), patients with no-reflow showed a higher rate of mortality than that observed in patients with reflow (30.2 vs. 18.3%, P<0.001). The multivariate Cox proportional hazards model identified the no-reflow phenomenon as an independent correlate of long-term mortality [adjusted hazard ratio (HR): 1.45; 95% confidence interval (CI): 1.12-1.86; P=0.004]. Time period-specific analyses demonstrated that the association between no-reflow and mortality was significant and stronger for short-term (<30 days) mortality (adjusted HR: 3.11; 95% CI: 1.91-5.05; P<0.001) but was not significant for longer-term mortality (30 days; adjusted HR: 1.12; 95% CI: 0.82-1.52; P=0.47). CONCLUSION: In patients with STEMI who had undergone primary PCI, the no-reflow phenomenon was an independent predictor of short-term but not long-term mortality.