Left ventricular contraction patterns in Takotsubo Syndrome and their correlation with long-term clinical outcome

Insulin resistance in Takotsubo syndrome

AIMS

Takotsubo syndrome (TTS) is an acute heart failure (AHF) syndrome mimicking the symptoms of acute myocardial infarction. Impaired outcome has been shown, making risk stratification and novel therapeutic concepts a necessity. We hypothesized insulin resistance with elevated plasma glucose and potentially myocardial glucose deprivation to contribute to the pathogenesis of TTS and investigated the therapeutic benefit of insulin in vivo.

METHODS AND RESULTS

First, we retrospectively analysed patient data of n = 265 TTS cases (85.7% female, mean age 71.1 ± 14.1 years) with documented initial plasma glucose from the Department of Cardiology of the University Hospital Heidelberg in Germany (May 2011 to May 2021). Median split of the study population according to glucose levels (≤123 mg/dL vs. >123 mg/dL) yielded significantly elevated mean heart rate (80.75 ± 18.96 vs. 90.01 ± 22.19 b.p.m., P < 0.001), left ventricular end-diastolic pressure (LVEDP, 18.51 ± 8.35 vs. 23.09 ± 7.97 mmHg, P < 0.001), C-reactive protein (26.14 ± 43.30 vs. 46.4 ± 68.6 mg/L, P = 0.006), leukocyte count (10.12 ± 4.29 vs. 15.05 ± 9.83/nL, P < 0.001), peak high-sensitive Troponin T (hs-TnT, 515.44 ± 672.15 vs. 711.40 ± 736.37 pg/mL, P = 0.005), reduced left ventricular ejection fraction (EF, 34.92 ± 8.94 vs. 31.35 ± 8.06%, P < 0.001), and elevated intrahospital mortality (2.3% vs. 12.1%, P = 0.002) in the high-glucose group (Student's t-test, Mann-Whitney U test, or chi-squared test). Linear regression indicated a significant association of glucose with HR (P < 0.001), LVEDP (P = 0.014), hs-TnT kinetics from admission to the next day (P < 0.001), hs-TnT the day after admission (P < 0.001), as well as peak hsTnT (P < 0.001). Logistic regression revealed significant association of glucose with a composite intrahospital outcome including catecholamine use, respiratory support, and resuscitation [OR 1.010 (1.004-1.015), P = 0.001]. To further investigate the potential role of glucose in TTS pathophysiology experimentally, we utilized an in vivo murine model of epinephrine (EPI)-driven reversible AHF. For this, male mice underwent therapeutic injection of insulin (INS, 1 IU/kg) or/and glucose (GLU, 0.5 g/kg) after EPI (2.5 mg/kg), both of which markedly improved mean EF (EPI 34.3% vs. EPI + INS + GLU 43.7%, P = 0.025) and significantly blunted mean hs-TnT (EPI 14 393 pg/mL vs. EPI + INS 6864 pg/mL at 24 h, P = 0.039). Particularly, insulin additionally ameliorated myocardial pro-inflammatory gene expression, suggesting an anti-inflammatory effect of acute insulin therapy.

CONCLUSIONS

Elevated initial plasma glucose was associated with adverse outcome-relevant parameters in TTS and may present a surrogate parameter of heightened catecholaminergic drive. In mice, insulin- and glucose injection both improved EPI-induced AHF and myocardial damage, indicating insulin resistance rather than detrimental effects of hyperglycaemia itself as the underlying cause. Future studies will investigate the role of HbA1c as a risk stratifier and of insulin-based therapy in TTS.

Comparative electrocardiographic analysis of midventricular and typical takotsubo syndrome

Introduction

Takotsubo syndrome (TTS) encompasses distinct variants, with midventricular (MV) as the most common atypical subtype. While electrocardiogram (ECG) abnormalities are well documented in typical TTS, they are less explored in MV-TTS.

Methods

A retrospective case-control study was conducted where ECGs were reviewed at three time points from symptom onset (within the first 12 h, at 48 h, and at 5-7 days) and compared between patients with typical TTS (n = 33) and those with MV-TTS (n = 27), as classified by ventriculography.

Results

12-h ECG findings revealed that typical TTS featured ST-segment elevation through anterior leads V3-V6, with maximal deviation in V3 (0.98 ± 0.99 mm) and V4 (0.91 ± 0.91 mm), whereas MV-TTS featured ST-segment depression in inferior leads (-0.24 ± 0.57 mm in II, -0.30 ± 0.52 mm in III, and -0.32 ± 0.47 mm in aVF) and in precordial leads V4-V6. In 48-h ECG findings, the most significant change was T wave inversion, which was more widespread and deeper in typical TTS, with the most pronounced negative T wave depths, exceeding 3 mm, observed in leads V3-V5; in contrast, in MV-TTS, T wave inversion was evident in fewer leads and showed less depth, with the most pronounced negative T waves reaching 1 mm at most in leads I, aVL, and V2. While the QTc interval was prolonged in both groups at 48 h, this prolongation was more pronounced in typical TTS than in MV-TTS (523 ± 52 ms vs. 487 ± 66 ms; p = 0.029). In ECGs at 5-7 days, results essentially returned to baseline.

Conclusion

Patients with MV-TTS exhibited a distinctive pattern of ECG abnormalities, marked by ST-segment depression in inferolateral leads, less profound and less extensive T wave inversion that mostly affected leads I, aVL and V2, and attenuated QT interval prolongation compared to typical TTS.

Prognostic factors of Takotsubo cardiomyopathy: a systematic review

Takotsubo cardiomyopathy (TCM), characterized by reversible ventricular dysfunction, has similar mortality to acute coronary syndrome. With the growing interest in the diagnosis of and interventions for TCM, many risk factors had been found to affect the prognosis of TCM patients, such as age, sex, and pre-existing diseases. Because of the incomplete understanding of the pathophysiologic mechanism in TCM, evidence-based medical therapy for this condition is lacking. Early intervention on risk factors may improve the outcomes of TCM. In this review, we sought to provide up-to-date evidence on risk factors and medical therapies that affect TCM outcome. We found that male sex, physical triggers, and certain comorbidities such as chronic kidney disease, malignant disease, higher body mass index, sepsis, chronic obstructive pulmonary disease, and anaemia were associated with poor TCM prognosis. In contrast, race, hyperlipidaemia, diabetes mellitus, and mood disorders were not clearly associated with TCM prognosis. We also reviewed the effect of medical therapies on TCM outcome, including angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, β-blockers, calcium channel blockers, and statins. The evidence that these medications confer a survival benefit on TCM patients is limited. Understanding these prognostic factors could help develop risk-stratification tools for TCM and establish effective prevention and interventions for this not-so-benign condition. Further multicentre clinical studies with large samples and meta-analyses of findings from previous studies are needed to address the inconsistent findings among the many potential risk factors for TCM.

Novel Imaging and Genetic Risk Markers in Takotsubo Syndrome

Takotsubo syndrome (TTS) is an increasingly recognized condition burdened by significant acute and long-term adverse events. The availability of novel techniques expanded the knowledge on TTS and allowed a more accurate risk-stratification, potentially guiding clinical management. The present review aims to summarize the recent advances in TTS prognostic evaluation with a specific focus on novel imaging and genetic markers. Parametric deformation analysis by speckle-tracking echocardiography, as well as tissue characterization by cardiac magnetic resonance imaging T1 and T2 mapping techniques, currently appear the most clinically valuable applications. Notwithstanding, computed tomography and nuclear imaging studies provided limited but promising data. A genetic predisposition to TTS has been hypothesized, though available evidence is still not sufficient. Although a genetic predisposition appears likely, further studies are needed to fully characterize the genetic background of TTS, in order to identify genetic markers that could assist in predicting disease recurrences and help in familial screening.