Ischemic burden reduction after chronic total occlusion percutaneous coronary intervention related to patient prognosis

Background Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) leads to major reductions in ischemic burden. However, to date, studies investigating if more ischemia reduction after CTO PCI translates into an improved patient prognosis, are lacking. Purpose To evaluate if change in absolute myocardial perfusion after CTO PCI is related to patient prognosis. Methods Between 2013–2019, 219 prospectively recruited patients with a CTO underwent quantitative [15O]H2O positron emission tomography perfusion imaging before and 3 months after successful CTO PCI in a single high-volume CTO PCI center (175 procedures/year). Changes in perfusion defect size (in myocardial segments) and hyperemic myocardial blood flow (MBF, in mL min–1 g–1) within the CTO territory after PCI were related to the combined endpoint of death or myocardial infarction (MI). Kaplan-Meier curves (log-rank test) and multivariable Cox regression (including covariates age, gender, prior MI, and left ventricular function) were used to analyze unadjusted and risk-adjusted event-free survivals with HR [95% CI]. Results Out of 213 (97%) patients with a median follow-up of 3.2 [2.1–4.7] years, 22 (10%) patients experienced the composite of death (19, 9%) or MI (5, 2%). Event-free survival was significantly improved in patients with a perfusion defect size reduction of ≥3 segments (N=132, 62%) after CTO PCI compared to <3 segments (p=0.01, risk-adjusted: p=0.02 with HR 0.36 [0.15–0.87]), as well in patients with increase in hyperemic MBF above the median of the population (delta >1.13 mL min–1 g–1) as compared to below the median (p<0.01, risk-adjusted: p=0.01 with HR 0.27 [0.10–0.75]). After PCI, patients with ≥1 segment residual perfusion defect size in the CTO territory at follow-up (N=114, 54%) had a significantly worse event-free survival compared to patients with no residual defect size (p<0.01, risk-adjusted: p=0.01 with HR 4.12 [1.35–12.59]), whereas patients with a residual hyperemic MBF >2.30 mL min–1 g–1 (N=105, 49%) showed a better event-free survival compared to patients with lower residual hyperemic MBF levels (p=0.02, risk-adjusted: p=0.04 with HR 0.33 [0.12–0.95]). Conclusions Patients with more ischemic burden reduction and less residual ischemia following CTO PCI showed a major improved survival free of death or MI. A limitation was the low absolute number of events that prohibited more extensive risk-adjustment of the analyses. Funding Acknowledgement Type of funding source: None

P5748Impact of specific crossing techniques in chronic total occlusion percutaneous coronary intervention on recovery of absolute myocardial perfusion

Background Multiple techniques in chronic coronary total occlusion (CTO) percutaneous coronary intervention (PCI) have been developed to cross CTOs. Purpose To compare recovery of quantitative myocardial blood flow (MBF) after different CTO PCI techniques. Methods Consecutive patients with [15O]H2O positron emission tomography perfusion imaging before and three months after successful CTO PCI were included. Change in quantitative hyperemic MBF, coronary flow reserve (CFR) and perfusion defect size were compared between antegrade wire escalation (AWE), retrograde wire escalation (RWE), antegrade dissection and reentry (ADR) and retrograde dissection and reentry (RDR), and further between specific subintimal crossing and reentry techniques. Results 193 patients were treated with AWE (N=90), RWE (N=24), ADR (N=35) and RDR (N=44). Significant improvements (all p<0.01) in hyperemic MBF (1.19±0.77, 0.94±0.65, 1.09±0.63, and 1.02±0.75 mL min–1 g–1, respectively), CFR (1.34±1.08, 1.14±1.09, 1.31±0.96, and 1.24±0.99, respectively), and perfusion defect size (3.17±2.13, 3.00±2.21, 2.74±2.09, and 2.93±1.92 segments, respectively) were comparable between the four approaches (p=0.40, p=0.84, and p=0.77, respectively). Recovery of hyperemic MBF was less pronounced after subintimal crossing with a knuckle-wire-technique compared to the use of CrossBoss in controlled ADR and RDR (p=0.02), and less after reentry with subintimal tracking and reentry (STAR) in ADR compared with controlled ADR (Stingray) or limited antegrade subintimal tracking (LAST) (p=0.02 and p<0.01). Conclusions Recovery of hyperemic MBF, CFR, and perfusion defect size was significant after CTO PCI and comparable between different crossing techniques. Improvement of hyperemic MBF was inferior after using the knuckle-wire subintimal crossing technique and STAR compared to other subintimal crossing and reentry techniques. Acknowledgement/Funding None