Impact of reversibility of no reflow phenomenon on 30-day mortality following percutaneous revascularization for acute myocardial infarction-insights from a 1,328 patient registry.

BACKGROUND: Occurrence of no reflow phenomenon during percutaneous coronary intervention (PCI) is associated with increased mortality. Although intracoronary medications can improve coronary flow, the effect on mortality is not known.

METHODS: Patients who had PCI for myocardial infarction (MI) at the Singapore National University Hospital from January 2000 to March 2004 were studied. Our analysis stratified patients into three groups according to the occurrence and persistence of no reflow during PCI. (1) Adequate reflow: without no reflow occurrence; (2) Reversible no reflow: no reflow occurred, but final thrombolysis in myocardial infarction (TIMI) 3 flow restored after intracoronary medications; and (3) Refractory no reflow: no reflow occurred and persisted, final TIMI flow < 3 despite medications. Thirty-day mortality was determined for each group.

RESULTS: A total of 1,328 patients (82% male), 703 (53%) underwent primary PCI and 625 (47%) rescue PCI were analyzed. Among the study patients, no reflow (including reversible and refractory) occurred in 135 patients (10.2%). Intracoronary verapamil, adenosine, nitroprusside, or a combination of drugs were used to treat the no reflow in 70.0%, 17.7%, 3.5%, and 8.8% of cases, respectively. Intracoronary medications successfully restored final TIMI 3 in 108 patients (80%, reversible no reflow). The remaining 27 patients (20%) have final TIMI < 3 (refractory no reflow). In comparison with the adequate reflow and reversible no reflow groups, those with refractory no reflow had an increased 30-day mortality (3.7% vs 2.8% vs 32.0%, P < 0.001). Logistic regression analyses showed that patients with refractory no reflow had a significantly higher 30-day mortality compared to patients with adequate reflow (P < 0.001) and reversible no reflow (P = 0.001), but no significant differences in the 30-day mortality between patients with adequate reflow and reversible no reflow (P = 0.157) were detected after adjusting for relevant covariates.

CONCLUSION: Among patients undergoing PCI for MI, reversible no reflow was associated with a significantly lower 30-day mortality compared with the refractory counterpart.