CTO PCI does not affect diastolic coupling in STEMI patients; elevated baseline LACI predicts mortality

Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) did not improve left ventricular systolic function. The left atrioventricular coupling index (LACI), derived from cardiovascular magnetic resonance (CMR), reflects diastolic atrioventricular coupling and has recently emerged as a parameter for diastolic dysfunction and a prognostic marker after acute myocardial infarction. We aimed to assess the impact of CTO PCI on LACI in patients with ST-elevation myocardial infarction (STEMI) and concurrent CTO METHODS: In this CMR substudy of the multicentre randomised controlled EXPLORE trial, 200 patients (mean age 60 ± 10 years, 88% male) underwent baseline CMR, and 178 patients had analysable 4-month follow-up CMR. LACI was defined as the ratio of left atrial and left ventricular end-diastolic volumes. The primary outcome was the effect of CTO PCI on LACI and change of LACI over time RESULTS: The significant improvement in LACI over time (Δ LACI - 1.0% [Q1-Q3: - 4.6 to 2.0], P = 0.005) was independent of CTO PCI or no-CTO PCI (P = 0.706). CTO PCI did not influence the change in LACI (- 0.8% [Q1-Q3: - 4.7 to 2.2], P = 0.122). Baseline LACI ≥20.6% was associated with an increased risk of all-cause death compared to LACI <20.6% after multivariable adjustment (hazard ratio 2.37, 95% CI: 1.27 to 4.45, P = 0.007) CONCLUSIONS: Among STEMI patients with a concurrent CTO, CTO PCI did not affect LACI at 4 months or its improvement over time. Elevated LACI early after STEMI independently predicted long-term all-cause mortality Clinical trial registration: The Evaluating Xience and left ventricular function in PCI on occlusiOns afteR STEMI (EXPLORE) trial; NTR1108 www.trialregister.nl, Date registered NTR: 30-okt-2007.