Hypothermia as an adjunctive therapy to percutaneous intervention after ST-elevation myocardial infarction-Effects on regional myocardial contractility

Abstract

Background: The effects of endovascular therapeutic hypothermia (ETH) in ST-elevation myocardial infarction (STEMI) regional contractility are unknown, and its impact on segmental contractility has still not been evaluated. We sought to evaluate segmental myocardial strain after ETH adjuvant to percutaneous coronary intervention (PCI) in STEMI.

Methods: We included patients who underwent 1.5T cardiovascular magnetic resonance exams 5 and 30 days after acute anterior or inferior STEMI in a previous randomized trial. Left ventricle (LV) strain was evaluated on infarcted, adjacent, and remote myocardium. Segmental circumferential (CS) and radial strains (RS) were measured using feature-tracking imaging. Repeated measures of analysis of variance were used for comparisons within time and treatment.

Results: Forty patients were divided into hypothermia (ETH, n = 29) and control (n = 11) groups, with 5210 LV segments. In ETH infarcted areas, RS (11.2 ± 16 vs 14.8 ± 15.2, p = 0.001) and CS (-5.4 ± 11.1 vs -8 ± 11.1, p = 0.001) showed recovery from 5-30 days compared to controls (11.4 ± 14 vs 13.1 ± 1 6.8, p = 0.09; -6.5 ± 10.6 vs -6.4 ± 12.5, p = 0.94). In control remote areas, RS (28 ± 18 vs 31.7 ± 18.5, p = 0.001) and CS (-15.5 ± 10.7 vs -17.1 ± 9, p = 0.001) improved from 5-30 days compared to ETH (28.6 ± 18.6 vs 29 ± 20, p = 0.44; -15.2 ± 10.4 vs -15.3 ± 10.6, p = 0.82). Transmural infarcted areas in ETH improved RS (11.8 ± 13.2 vs 8.17 ± 14.7, p = 0.001) and CS (-6.1 ± 10.9 vs.-3.1 ± 11.3, p = 0.001) compared to controls, with better contractility at 30 days.

Conclusion: In anterior or inferior STEMI patients, ETH adjuvant to PCI is associated with significant improvement in RS and CS of infarcted areas, including transmural segments, but not in remote area. This might further increase our pathophysiological knowledge on early LV remodeling and ultimately suggest potential clinical value.

Availability of data and materials: The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Keywords: Cardiac magnetic resonance; Myocardial strain; Percutaneous coronary intervention; ST-elevation myocardial infarction; Therapeutic hypothermia.