Improved recovery of regional left ventricular function after PCI of chronic total occlusion in STEMI patients: a cardiovascular magnetic resonance study of the randomized controlled EXPLORE trial

Contains fulltext : 177042.pdf (publisher's version ) (Open Access)BACKGROUND: The Evaluating Xience and left ventricular function in PCI on occlusiOns afteR STEMI (EXPLORE) trial did not show a significant benefit of percutaneous coronary intervention (PCI) of the concurrent chronic total occlusion (CTO) in ST-segment elevation myocardial infarction (STEMI) patients on global left ventricular (LV) systolic function. However a possible treatment effect will be most pronounced in the CTO territory. Therefore, we aimed to study the effect of CTO PCI compared to no-CTO PCI on the recovery of regional LV function, particularly in the CTO territory. METHODS: Using cardiovascular magnetic resonance (CMR) we studied 180 of the 302 EXPLORE patients with serial CMR (baseline and 4 months follow-up). Segmental wall thickening (SWT) was quantified on cine images by an independent core laboratory. Dysfunctional segments were defined as SWT < 45%. Dysfunctional segments were further analyzed by viability (transmural extent of infarction (TEI) </=50%.). All outcomes were stratified for randomization treatment. RESULTS: In the dysfunctional segments in the CTO territory recovery of SWT was better after CTO PCI compared to no-CTO PCI (DeltaSWT 17 +/- 27% vs 11 +/- 23%, p = 0.03). This recovery was most pronounced in the dysfunctional but viable segments(TEI < 50%) (DeltaSWT 17 +/- 27% vs 11 +/- 22%, p = 0.02). Furthermore in the CTO territory, recovery of SWT was significantly better in the dysfunctional segments in patients with Rentrop grade 2-3 collaterals compared to grade 0-1 collaterals to the CTO (16 +/- 26% versus 11 +/- 24%, p = 0.04). CONCLUSION: CTO PCI compared with no-CTO PCI is associated with a greater recovery of regional systolic function in the CTO territory, especially in the dysfunctional but viable segments. Further research is needed to evaluate the use of CMR in selecting post-STEMI patients for CTO PCI and the effect of regional LV function recovery on clinical outcome. TRIAL REGISTRATION: Trialregister.nl NTR1108 , Date registered NTR: 30-okt-2007

Prevalence and impact of a chronic total occlusion in a non-infarct-related artery on long-term mortality in diabetic patients with ST elevation myocardial infarction

Background Recently, a chronic total occlusion (CTO) in a non-infarct-related artery (non-IRA) and not multivessel disease (MVD) alone was identified as an independent predictor of mortality after ST elevation myocardial infarction (STEMI). Patients with diabetes mellitus (DM) constitute a patient group with a high prevalence of MVD and high mortality after STEMI. The prevalence of CTO in a non-IRA was studied and its impact on long-term mortality in STEMI patients with DM was investigated. Methods Between 1997 and 2007 4506 patients with STEMI were admitted and treated with primary percutaneous coronary intervention (PCI). Patients with DM were identified. The patients were categorised as having single vessel disease (SVD), MVD without CTO and CTO based on the angiogram before PCI. Results A total of 539 patients (12%) had DM. MVD with or without a CTO was present in 33% of non-diabetic patients and in 51% of diabetic patients. The prevalence of a CTO in a non-IRA was 21% in STEMI patients with DM and 12% in STEMI patients without DM (p <0.01). Kaplan-Meier estimates for 5-year mortality in STEMI patients with DM were 25%, 21% and 47% in patients with SVD, MVD without a CTO and MVD with a CTO in a non-IRA, respectively. A CTO in a non-IRA was an independent predictor of 5-year mortality (HR 2.2, 95% CI 1.3 to 3.5, p <0.01). Conclusion The prevalence of a CTO in a non-IRA was increased in STEMI patients with DM. The presence of a CTO in a non-IRA was a strong and independent predictor of 5-year mortality. These results suggest that, particularly in the high-risk subgroup of STEMI patients with DM, MVD has prognostic implications only if a concurrent CTO is presen

Percutaneous Intervention for Concurrent Chronic Total Occlusions in Patients With STEMI: The EXPLORE Trial

BACKGROUND: In 10% to 15% of patients with ST-segment elevation myocardial infarction (STEMI), concurrent coronary chronic total occlusion (CTO) in a non-infarct-related artery is present and is associated with increased morbidity and mortality. OBJECTIVES: The EXPLORE (Evaluating Xience and Left Ventricular Function in Percutaneous Coronary Intervention on Occlusions After ST-Elevation Myocardial Infarction) trial evaluated whether patients with STEMI and concurrent CTO in a non-infarct-related artery benefit from additional percutaneous coronary intervention (PCI) of CTO shortly after primary PCI. METHODS: From November 2007 through April 2015, we enrolled 304 patients with acute STEMI who underwent primary PCI and had concurrent CTO in 14 centers in Europe and Canada. A total of 150 patients were randomly assigned to early PCI of the CTO (CTO PCI), and 154 patients were assigned to conservative treatment without PCI of the CTO (no CTO PCI). Primary outcomes were left ventricular ejection fraction (LVEF) and left ventricular end diastolic volume (LVEDV) on cardiac magnetic resonance imaging after 4 months. RESULTS: The investigator-reported procedural success rate in the CTO PCI arm of the trial was 77%, and the adjudicated success rate was 73%. At 4 months, mean LVEF did not differ between the 2 groups (44.1 +/- 12.2% vs. 44.8 +/- 11.9%, respectively; p = 0.60). Mean LVEDV at 4 months was 215.6 +/- 62.5 ml in the CTO PCI arm versus 212.8 +/- 60.3 ml in the no-CTO PCI arm (p = 0.70). Subgroup analysis revealed that patients with CTO located in the left anterior descending coronary artery who were randomized to the CTO PCI strategy had significantly higher LVEF compared with patients randomized to the no-CTO PCI strategy (47.2 +/- 12.3% vs. 40.4 +/- 11.9%; p = 0.02). There were no differences in terms of 4-month major adverse coronary events (5.4% vs. 2.6%; p = 0.25). CONCLUSIONS: Additional CTO PCI within 1 week after primary PCI for STEMI was feasible and safe. In patients with STEMI and concurrent CTO, we did not find an overall benefit for CTO PCI in terms of LVEF or LVEDV. The finding that early CTO PCI in the left anterior descending coronary artery subgroup was beneficial warrants further investigation. (Evaluating Xience and Left Ventricular Function in Percutaneous Coronary Intervention on Occlusions After ST-Segment Elevation Myocardial Infarction; NTR1108)