Ischemic preconditioning affects phosphosites and accentuates myocardial stunning while reducing infarction size in rats.

Background and aims: Ischemic preconditioning (IPC), i.e., brief periods of ischemia, protect the heart from subsequent prolonged ischemic injury, and reduces infarction size. Myocardial stunning refers to transient loss of contractility in the heart after myocardial ischemia that recovers without permanent damage. The relationship between IPC and myocardial stunning remains incompletely understood. This study aimed primarily to examine the effects of IPC on the relationship between ischemia duration, stunning, and infarct size in an ischemia-reperfusion injury model. Secondarily, this study aimed to examine to which extent the phosphoproteomic changes induced by IPC relate to myocardial contractile function. Methods and results: Rats were subjected to different durations of left anterior descending artery (LAD) occlusion, with or without preceding IPC. Echocardiograms were acquired to assess cardiac contraction in the affected myocardial segment. Infarction size was evaluated using triphenyl tetrazolium chloride staining. Phosphoproteomic analysis was performed in heart tissue from preconditioned and non-preconditioned animals. In contrast to rats without IPC, reversible akinesia was observed in a majority of the rats that were subjected to IPC and subsequently exposed to ischemia of 13.5 or 15 min of ischemia. Phosphoproteomic analysis revealed significant differential regulation of 786 phosphopeptides between IPC and non-IPC groups, with significant associations with the sarcomere, Z-disc, and actin binding. Conclusion: IPC induces changes in phosphosites of proteins involved in myocardial contraction; and both accentuates post-ischemic myocardial stunning and reduces infarct size.

Temporal electrocardiographic changes in anterior ST elevation myocardial infarction versus the Takotsubo syndrome.

Background: Electrocardiography (ECG) on admission is similar in ST elevation myocardial infarction (STEMI) and Takotsubo syndrome (TTS). ECG on admission has been extensively investigated and compared between STEMI and TTS, however, only a few studies have compared temporal ECG. Our aim was to compare ECG in anterior STEMI versus female TTS from admission to day 30. Methods: Adult patients with anterior STEMI or TTS treated at Sahlgrenska University Hospital (Gothenburg, Sweden) from December 2019 to June 2022 were prospectively enrolled. Baseline characteristics, clinical variables and ECGs from admission to day 30 were analyzed. Using a mixed effects model, we compared temporal ECG between female patients with anterior STEMI or TTS, as well as between female and male patients with anterior STEMI. Results: A total of 101 anterior STEMI patients (31 female, 70 male) and 34 TTS patients (29 female, 5 male) were included. The temporal pattern of T wave inversion was similar between female anterior STEMI and female TTS, as well as between female and male anterior STEMI. ST elevation was more common, whereas QT prolongation was less common, in anterior STEMI compared with TTS. Q wave pathology was more similar between female anterior STEMI and female TTS than between female and male anterior STEMI. Conclusions: The pattern of T wave inversion and Q wave pathology from admission to day 30 was similar in female patients with anterior STEMI and female patients with TTS. Temporal ECG in female patients with TTS may be interpreted as following a "transient ischemic" pattern.

ECG differences and ECG predictors in patients presenting with ST segment elevation due to myocardial infarction versus takotsubo syndrome.

Background: Previous studies comparing electrocardiogram (ECG) in Takotsubo syndrome (TS) versus ST elevation myocardial infarction (STEMI) included TS patients without ST elevation, did not consider the culprit lesion in STEMI or had groups that were unbalanced regarding sex and age. Accounting for these factors, we sought to conduct a more reliable comparison of ECG in TS with ST-elevation (STE-TS) versus STEMI. The secondary aim was to investigate if ST segment changes, T wave inversion or prolonged QT interval predicted ventricular arrhythmia or death in STE-TS and STEMI. Methods: All STE-TS patients who presented at Sahlgrenska University Hospital between 2008 and 2019 were matched by sex and age to STEMI patients. STEMI patients were subcategorized according to whether or not the culprit lesion was located in the left anterior descending artery (LAD). Baseline characteristics, in-hospital outcomes and admission ECGs were analyzed. Results: 104 STE-TS patients were sex- and age-matched with 274 STEMI patients (113 LAD-STEMI, 161 non-LAD STEMI). Admission ECG in STE-TS was more similar to LAD STEMI than non-LAD STEMI. Reciprocal ST depression was less common in STE-TS (7/104, 6.7%) compared with STEMI (112/274, 41%; p= < 0.001). The sum of all ST elevations and the sum of all ST-deviations predicted life-threatening ventricular arrhythmia (LTVA) or death in LAD STEMI but not in STE-TS. Conclusions: In conclusion, admission ECG in STE-TS was similar to LAD STEMI but reciprocal ST depression was less common in STE-TS compared with STEMI overall. ST segment changes predicted LTVA or death in STEMI but not in STE-TS.

Risk of in-hospital life-threatening ventricular arrhythmia or death after ST-elevation myocardial infarction vs. the Takotsubo syndrome.

AIMS: The risk of life-threatening ventricular arrhythmias (LTVA) has been reported to be lower in Takotsubo syndrome (TS) compared with ST-elevation myocardial infarction (STEMI). However, the extent to which these differences relate to the fact that most patients with TS are women (who have a lower risk of LTVA) and a relatively larger proportion of patients with STEMI are men is incompletely understood. We aimed to investigate the risk of LTVA or death in sex-matched and age-matched patients with TS, anterior STEMI, and non-anterior STEMI. METHODS AND RESULTS: We systematically reviewed the charts of all patients with TS who were treated at Sahlgrenska University Hospital (Gothenburg, Sweden) between 2008 and 2019. A total of 155 patients with confirmed TS (according to the European Society of Cardiology diagnostic criteria for TS) were sex-matched and age-matched 1:1:1 to patients with anterior and non-anterior STEMI. Baseline characteristics and in-hospital outcomes were recorded directly from the patient charts for all patients, and all admission electrocardiographs were analysed. The primary outcome was the composite of death or LTVA [defined as sustained ventricular tachycardia (>30 s) or ventricular fibrillation] within 72 h. The risk of LTVA or death within 72 h after admission was considerably lower in TS (2.6%) vs. anterior STEMI (14%; P = 0.002) and non-anterior STEMI (9.0%; P = 0.02), despite similar or greater risks of acute heart failure, and similar risks of cardiogenic shock. Compared with STEMI, TS was associated with a lower risk of sustained and non-sustained ventricular tachycardia and ventricular fibrillation. CONCLUSIONS: In a predominantly female age-matched and sex-matched cohort of patients with TS, anterior STEMI, and non-anterior STEMI, the adjusted risk of in-hospital LTVA or death was considerably lower in TS compared with STEMI, despite similar or greater risk of acute heart failure and similar risk of cardiogenic shock.

Clinical management in the takotsubo syndrome.

Introduction: Takotsubo syndrome (TS) is an increasingly recognized acute heart failure syndrome which is self-limiting in most cases but can result in life-threatening complications. TS is difficult to distinguish from acute myocardial infarction (AMI) early in the disease course and currently lacks evidence-based treatment recommendations. Areas covered: Based on the available literature this systematic review discusses the clinical management of patients with TS during (i) the diagnostic workup; (ii) acutely after establishing the TS diagnosis; and (iii) after recovery of cardiac function. Expert commentary: Since TS is self-limiting in most cases it is recommended to refrain from unnecessary treatment (the do no harm principle) when managing patients with TS. The management of patients with TS should focus on careful monitoring of ECG and hemodynamics, and on preventing and treating complications. Because catecholamine-mediated inotropic overstimulation is implicated in the pathogenesis of TS, and because inotropic drugs have been associated with worse outcomes for patients with TS, we recommend the treating physician to avoid these drugs. Instead, mechanical assist devices should be considered early for patients with TS who develop cardiogenic shock with signs of end-organ hypo-perfusion.