Modified balloons to prepare severely calcified coronary lesions before stent implantation: a systematic review and meta-analysis of randomized trials.

BACKGROUND: The performance of modified balloons (namely cutting or scoring balloons) to prepare severely calcified lesions in patients undergoing percutaneous coronary intervention (PCI) remains controversial. We investigated the clinical and imaging outcomes of patients undergoing PCI assigned to modified balloon therapy to prepare severely calcified coronary lesions before stent implantation. METHODS: In this meta-analysis, we aggregated the study-level data from trials enrolling invasively treated patients who were randomly assigned to modified balloon or control therapy to prepare severely calcified lesions before stenting. The primary outcome was major adverse cardiac events (MACE), including death, myocardial infarction (MI), and repeat revascularization. The secondary outcomes included the individual components of the primary outcome, coronary perforation and final minimal stent area (MSA) as measured by intracoronary imaging. RESULTS: A total of 648 participants in six trials were allocated to modified balloon therapy (n = 335) or control therapy (semi-compliant, non-compliant, or super high-pressure balloon, n = 313). The median follow-up was 11 months. Overall, MACE occurred in 8.96% of patients assigned to a modified balloon and 12.78% of patients assigned to control therapy [risk ratio = 0.70, 95% confidence interval (CI) 0.35-1.39; P = 0.24]. There was a significant treatment effect-by-modified balloon type interaction for the outcome MACE in patients assigned to cutting balloon compared with control therapy [RR = 0.40 (0.28-0.56), P for interaction (Pint) < 0.001]. Patients treated with a modified balloon compared with control therapy showed neither a significant difference for the other clinical outcomes nor for final MSA [standardized mean difference = 0.67 (- 0.71, 2.06); P = 0.26]. CONCLUSIONS: In patients treated with PCI for severely calcific coronary artery disease a strategy of lesion preparation with a modified balloon before stenting does not improve clinical or imaging outcomes compared with control therapy. The different performance of cutting and scoring balloons warrants further investigation.