Predilation in Primary Percutaneous Coronary Intervention

Background: In primary percutaneous coronary intervention (pPCI), balloon predilation is frequently carried out before stenting but there is a lack of data regarding optimal balloon size and the effect of balloon size on procedural and clinical outcomes. Aims: This study compares small balloon predilation (≤50% of proximal vessel diameter) with large balloon predilation (>50% of proximal vessel diameter) in pPCI. Methods: This multicentre prospective observational study included consecutive ST elevation MI (STEMI) patients undergoing pPCI at three tertiary centres in Egypt. Demographic, clinical and angiographic data were collected for all the patients. The primary outcome was the presence of no reflow at the conclusion of the procedure and secondary outcomes included procedural complications - no reflow, dissection, abrupt vessel closure, fluoroscopy time and procedural time - and clinical outcomes - in-hospital left ventricular ejection fraction (LVEF), cardiogenic shock, stent thrombosis, ventricular fibrillation, stroke, death, ST-segment resolution >50% 1 hour after PCI and LVEF at discharge. Results: A total of 384 pPCI procedures were included. The small balloon group (n=222) and the large balloon group (n=162) were comparable in terms of baseline characteristics. The large balloon group had a significantly higher incidence of no reflow (n=23 [14.2%] versus n=6 [2.7%], p<0.001), procedural complications: n=31 [19.4%] versus n=10 [4.5%], p<0.001) and contrast volume (190.4 ± 40.2 ml versus 177.4 ± 29.4 ml, p=0.0003) compared to the small balloon group. ST-segment resolution >50% after PCI was more frequent in the small balloon group (n=182 [81.98%] versus n=109 [67.28%], p<0.001). Conclusion: This study suggests that using a smaller balloon size for predilation in pPCI is associated with improved coronary flow, reduced procedural complications and better ST-segment resolution.