Angiography-Derived Index of Microcirculatory Resistance to Define the Risk of Early Discharge in STEMI

Abstract

BACKGROUND: Patients with ST-segment–elevation myocardial infarction but no coronary microvascular injury are at low risk of early cardiovascular complications (ECC). We aim to assess whether nonhyperemic angiography-derived index of microcirculatory resistance (NH-IMR angio ) could be a user-friendly tool to identify patients at low risk of ECC, potentially candidates for expedited care pathway and early hospital discharge. METHODS: Retrospective analysis of 2 independent, international, prospective, observational cohorts included 568 patients with ST-segment–elevation myocardial infarction. NH-IMR angio was calculated based on standard coronary angiographic views with 3-dimensional-modeling and computational analysis of the coronary flow. RESULTS: Overall, ECC (a composite of cardiovascular death, cardiogenic shock, acute heart failure, life-threatening arrhythmias, resuscitated cardiac arrest, left ventricular thrombus, post-ST-segment–elevation myocardial infarction mechanical complications, and rehospitalization for acute heart failure or acute myocardial infarction at 30 days follow-up), occurred in 54 (9.3%) patients. NH-IMR angio was significantly correlated with pressure/thermodilution-based index of microcirculatory resistance (r=0.607; P <0.0001) and demonstrated good accuracy in predicting ECC (area under the curve, 0.766 [95% CI, 0.706–0.827]; P <0.0001). Importantly, ECC occurred more frequently in patients with NH-IMR angio ≥40 units (18.1% versus 1.4%; P <0.0001). At multivariable analysis, NH-IMR angio provided incremental prognostic value to conventional clinical, angiographic, and echocardiographic features (adjusted-odds ratio, 14.861 [95% CI, 5.177–42.661]; P <0.0001). NH-IMR angio <40 units showed an excellent negative predictive value (98.6%) in ruling out ECC. Discharging patients with NH-IMR angio <40 units at 48 hours after admission would reduce the total in-hospital stay by 943 days (median 2 [1–4] days per patient). CONCLUSIONS: NH-IMR angio is a valuable risk-stratification tool in patients with ST-segment–elevation myocardial infarction. NH-IMR angio guided strategies to early discharge may contribute to safely shorten hospital stay, optimizing resources utilization.

Treatment and Care of Patients with ST-Segment Elevation Myocardial Infarction—What Challenges Remain after Three Decades of Primary Percutaneous Coronary Intervention?

“…Various versions of angiography-derived IMR have been proposed in recent years, all showing good diagnostic accuracy in detecting an abnormal IMR (comparable to its invasive counterpart), and good correlations with clinical outcomes and MVO detection using cMRI in STEMI patients [134,135]. More recently, angiography-derived IMR (namely, IMR angio ) has shown a 98% negative predictive value in ruling out the occurrence of in-hospital and 30-day adverse events in STEMI patients, configuring itself as a promising tool to non-invasively risk-stratify STEMI patients [136].…”

Perfect Wedding Between Patient With STEMI and Angiography-Derived Indexes of Coronary Physiology

“…The present article by Scarsini et al 6 explores the application of angiography-derived indexes of coronary physiology, namely angiography-derived IMR, in an important clinical scenario. Patients with ST-segment-elevation myocardial infarction (STEMI) received as soon as possible coronary artery angiography and revascularization of the culprit lesion.…”

“…The article by Scarsini et al 6 suggests that the first question can be solved by the systematic offline computation of angiography-derived IMR. The authors calculated the angiography-derived IMR value in 568 patients with STEMI.…”