Long-Term Clinical Outcomes in Patients With an Acute ST-Segment-Elevation Myocardial Infarction Stratified by Angiography-Derived Index of Microcirculatory Resistance.

Aims: Despite the prognostic value of coronary microvascular dysfunction (CMD) in patients with ST-segment-elevation myocardial infarction (STEMI), its assessment with pressure-wire-based methods remains limited due to cost, technical and procedural complexities. The non-hyperaemic angiography-derived index of microcirculatory resistance (NH IMR _angio ) has been shown to reliably predict microvascular injury in patients with STEMI. We investigated the prognostic potential of NH IMR _angio as a pressure-wire and adenosine-free tool. Methods and Results: NH IMR _angio was retrospectively derived on the infarct-related artery at completion of primary percutaneous coronary intervention (pPCI) in 262 prospectively recruited STEMI patients. Invasive pressure-wire-based assessment of the index of microcirculatory resistance (IMR) was performed. The combination of all-cause mortality, resuscitated cardiac arrest and new heart failure was the primary endpoint. NH IMR _angio showed good diagnostic performance in identifying CMD (IMR > 40U); AUC 0.78 (95%CI: 0.72-0.84, p < 0.0001) with an optimal cut-off at 43U. The primary endpoint occurred in 38 (16%) patients at a median follow-up of 4.2 (2.0-6.5) years. On survival analysis, NH IMR _angio > 43U (log-rank test, p < 0.001) was equivalent to an IMR > 40U(log-rank test, p = 0.02) in predicting the primary endpoint (hazard ratio comparison p = 0.91). NH IMRangio > 43U was an independent predictor of the primary endpoint (adjusted HR 2.13, 95% CI: 1.01-4.48, p = 0.047). Conclusion: NH IMR _angio is prognostically equivalent to invasively measured IMR and can be a feasible alternative to IMR for risk stratification in patients presenting with STEMI.
Competing Interests: GD reports grants from Miracor Medical SA, outside the submitted work. In addition, GD has a patent PCT/US20/55240 pending. AB reports grants from Boston Scientific, personal fees from Boston Scientific, personal fees from Abbott, personal fees from Medtronic, personal fees from Phillips, outside the submitted work. HG-G reports institutional research grants from Medtronic, Boston Scientific, Abbott, Biotronik, Neovasc, Corflow, Shockwave, Chiesi, outside the submitted work. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2021 Kotronias, Terentes-Printzios, Shanmuganathan, Marin, Scarsini, Bradley-Watson, Langrish, Lucking, Choudhury, Kharbanda, Garcia-Garcia, Channon, Banning and De Maria.)