Clinical significance of no-reflow in different stages of primary angioplasty among patients with acute myocardial infarctions

Abstract

Background: The coronary no-reflow (NR) phenomenon, which is associated with poor clinical outcomes, is usually referred to as a post-percutaneous coronary intervention (PCI) state. NR can occur in different stages of the PCI procedure, not only including the post-stenting stage, but from balloon pre-dilation to pre-stenting. The clinical significance of NR in the different stages of the PCI procedure is unclear. The purpose of the current study was to analyze the clinical and angiographic characteristics, the prognosis for NR patients in the aforementioned two stages and to determine the predictors of NR in the early stage. Methods: Between January 2009 and December 2013, a total of 420 consecutive patients with ST-segment elevation myocardial infarction (STEMI) underwent primary PCI. Sixty-three patients (15%) with NR constituted the study population. The patients were divided into an early NR group and a subsequent NR group. The clinical and angiographic findings were compared between the two groups. Multivariate logistic regression was used to determine the predictors for early NR. The long-term clinical outcomes after PCI were analyzed. Results: Regarding the baseline characteristics, we identified that the early NR group had statistically significant effects on the higher percentage of diabetes mellitus (42.9% vs. 20%), lower admission systolic blood pressure (SBP) (102.2±8.3 mmHg vs. 110.5±7.6 mmHg), higher percentage of Killip classification III (71.4% vs. 45.7%,) and longer reperfusion time (7.1±2.3 h vs. 5.88±2.2 h) compared to the subsequent NR group. There were significant differences between the two groups with respect to the percentage of initial thrombolysis in myocardial infarction (TIMI) flow 0/1 (64.3% vs. 37.1%), target lesion length (31.4±13.6 mm vs. 20.5±17.3 mm) and thrombus score ⩾4 (67.9% vs. 42.9%; p<0.05 for all). Multiple stepwise logistic regression analysis indicated that an admission SBP <100 mmHg (OR=4.580; 95% CI=1.385–15.150; p=0.0130), reperfusion time ⩾6 h (OR=4.978; 95% CI=1.468–16.882; p=0.010) and a thrombus score ⩾4 (OR=2.708; 95% CI=0.833–8.799; p=0.008) were the independent determinants of the early NR. During a 1-year follow-up, the all-cause mortality and overall major adverse cardiac events (MACEs) in the early NR group occurred significantly more often than in the subsequent NR group (28.6% vs. 5.7% and 35.7% vs. 14.3%, respectively, p <0.05). The early NR group had a lower left ventricular ejection fraction (LVEF) (42.5±4.7 vs. 47.8±3.5, p <0.001) and a larger left ventricular end diastolic diameter (LVEDD) (56.0±4.0 vs. 51.5 ±4.7, p=0.001) at the end of the follow-up. Conclusion: Early NR patients during primary PCI have more severe baseline clinical and angiographic characteristics, as well as a poorer long-term prognosis.