Comparison of Contractility Patterns on Left Ventriculogram Versus Longitudinal Strain by Echocardiography in Patients With Takotsubo Cardiomyopathy

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.

Coronary Microvascular Dysfunction in Takotsubo Syndrome Assessed by Angiography-Derived Index of Microcirculatory Resistance: A Pressure-Wire-Free Tool

Background: Coronary microvascular dysfunction (CMD) has been proposed as a key mechanism in Takotsubo syndrome (TTS). The non-hyperaemic angiography-derived index of microcirculatory resistance (NH-IMRangio) has been validated as a pressure-wire-free tool for the assessment of coronary microvasculature. We aimed to study the presence of CMD in TTS patients and its association with levels of cardiac biomarkers and systolic dysfunction patterns. Methods: We recruited 181 consecutive patients admitted for TTS who underwent cardiac angiography at a tertiary center from January 2014 to January 2021. CMD was defined as an NH-IMRangio ≥ 25. Plasma levels of NT-proBNP, high-sensitive cardiac troponin T (hs-cTnT) and the left ventricular ejection fraction (LVEF) by echocardiography were measured at admission. Results: Mean age was 75.3 years, 83% were women and median LVEF was 45%. All patients presented CMD (NH-IMRangio ≥ 25) in at least one epicardial coronary artery. The left anterior descending artery (LAD) showed higher median NH-IMRangio values than left circumflex (LCx) and right coronary arteries (RCA) (44.6 vs. 31.3 vs. 36.1, respectively; p < 0.001). NH-IMRangio values differed among ventricular contractility patterns in the LAD and RCA (p = 0.0152 and 0.0189, respectively) with the highest values in the mid-ventricular + apical and mid-ventricular + basal patterns. NT-proBNP levels, but not high-sensitive cardiac troponin T (hs-cTnT), were correlated with both the degree and the extent of CMD in patients with TTS. Lower LVEF was also associated with higher NH-IMRangio values. Conclusions: CMD is highly prevalent in patients admitted for TTS and is associated with both a higher degree of systolic dysfunction and higher BNP levels, but not troponin.