Incremental prognostic value of global longitudinal strain to the coronary microvascular resistances in Takotsubo patients

Background: Global longitudinal strain (GLS) allows an accurate assessment of left ventricular function with prognostic value. We aimed to evaluate whether the assessment of GLS in the acute phase of Takotsubo syndrome (TTS) provides incremental prognostic value to the degree of impaired microvascular resistance (MR) in TTS patients at 1-year follow-up. Methods: We recruited patients admitted for TTS who underwent cardiac angiography and echocardiography from January 2017 to June 2020. Left anterior descending coronary artery non-hyperaemic angiography-derived index of microcirculatory resistance (LAD NH-IMRangio) was calculated. NT-proBNP, high-sensitive cardiac troponin T (hs-cTnT), left ventricular ejection fraction (LVEF) and GLS were measured at admission. Major adverse cardiac events (MACE) were defined as the composite of cardiovascular death, repeat hospitalizations for heart failure (HF) and acute myocardial infarctions. Results: 67 patients had both GLS and NH-IMRangio available and were included in the study. Median age was 75.2 years and 88% were women. Rate of MACE at 1-year was 13.4%. Kaplan-Meier curves showed higher rates of MACE at 1-year in patients with both higher LAD NH-IMRangio and GLS values compared with those with higher LAD NH-IMRangio and lower GLS values (33.3% vs. 11.1%; p = 0.049). NT-proBNP levels at admission and the recovery of LVEF were correlated with GLS values while MR and hs-cTnT were not. Conclusion: GLS provides incremental prognostic value to the degree of impaired MR in TTS patients. The combination of a poorer GLS with a higher degree of impaired MR was associated with a higher rate of MACE in these patients.