Prognostic value of early sustained ventricular arrhythmias in ST-elevation myocardial infarction treated by primary percutaneous coronary intervention: a sub-study of VALIDATE-SWEDEHEART trial

Incidence and outcomes of acute myocardial infarction with arrhythmic onset: A retrospective cohort study

INTRODUCTION

Patients with acute coronary syndrome (ACS) have concomitant ventricular arrhythmic events (VA). Literature data are conflicting regarding short- and long-term prognosis. International guidelines do not recommend defibrillator (ICD) implantation in the first 40 days after a myocardial infarction. However, some patients may have an increased arrhythmic risk and deserve closer monitoring.

PURPOSE

The aim of our study was to define the incidence of arrhythmic events in a population of patients admitted for ACS to the Cardiac Intensive Care Unit (CICU) of a tertiary center and to determine the short- and long-term prognosis in patients with arrhythmic onset compared with patients without arrhythmic onset.

METHODS

This is a single-center retrospective cohort data analysis of 1587 consecutive patients admitted with a diagnosis of ACS to the CICU of Niguarda Hospital of Milan, from 2014 to 2022. We classified the patients into two groups according to the arrhythmias at presentation: VA (sustained VT or VF) and no-VA. Kaplan-Meier (KM) estimated the probability of remaining event free in the time after ACS and were compared between VA and no-VA groups, using the log-rank test. Cox regression analysis was used to explore the association of specific variables with the occurrence of cardiac events in univariate and multivariate analysis. Statistical analyses were performed with R 42.0 statistical package (R Core Team, Vienna, Austria).

RESULTS

Among 1587 ASC patients, 4.6 % had arrhythmic onset (4.0 had a diagnosis of VF and 0.6 % of VT). Patients with VA were significantly younger (63 y. vs 67 y., p = 0.026) and had a lower incidence of cardiovascular risk factors, such as hypertension and dyslipidemia, compared with no-VA group. VA group had a higher risk of arrhythmias during the hospitalization (9.6 % vs 1.3 %, p < 0.001) and had a clinical course characterized by a significantly higher use of mechanical support with intra-aortic balloon pumps (IABP, 35.6 % vs. 6.8 %, p < 0.001) and a greater use of inotropic drugs (34 % vs. 9 %, p < 0.001). We observed in VA group a six-fold increase in-hospital mortality (23 % vs 4 %, p < 0.001), identifying arrhythmic presentation as a marker of worse in-hospital prognosis in patients admitted with ACS. Likewise, mortality at 40 days after the acute event was higher in the VA group than in the no-VA group (22 % vs. 5 %, p < 0.001). Conversely, during a median follow-up of 5.9 years, VA onset did not affect long-term mortality in patients discharged alive.

CONCLUSION

In this long-term follow-up retrospective registry involving a large cohort of patients with ACS admitted to the CICU, concomitant VA at admission was found to be linked with an increase in in-hospital arrhythmic complications and in-hospital mortality. The mortality rate at 40 days post-ACS was also notably higher in the VA group. This study underscores the complexity of arrhythmic presentation in ACS patients, emphasizing the critical need for vigilant monitoring throughout their hospitalization and particularly in the initial 6 weeks following the event index. This heightened surveillance is justified by the documented elevated levels of morbidity and mortality during this phase.

Ventricular Tachycardia and Hospital Readmission in Patients Discharged From the Hospital After an Acute Myocardial Infarction

Background

Although ventricular tachycardia (VT) occurring during hospitalization for an acute myocardial infarction (AMI) increases mortality risk, its relationship with 30-day postdischarge rehospitalization has not been examined.

Methods

Using data from the Worcester Heart Attack Study, we examined the association between early (during the first 48 hours of admission) and late (after 48 hours from admission) VT with 30-day postdischarge all-cause and cardiovascular disease (CVD)-related rehospitalization while analytically controlling for several demographic and clinical factors.

Results

The study population consisted of 3534 patients who were hospitalized with an AMI between 2005 and 2015 (average age, 67.2 years; 40.7% women); VT occurred in 452 patients (13.7%), with the majority of instances (81.2%) occurring within 48 hours of admission. The 30-day all-cause rehospitalization rate was 17.3%, with 70.9% of the hospitalizations related to CVD. The odds of rehospitalization were 1.63 times (95% confidence interval [CI] = 0.99-2.69) and 1.12 times (95% CI = 0.83-1.51) higher for patients with AMI who developed late VT and early VT, respectively, compared to patients who did not develop VT. The risk of rehospitalization among patients with late VT was higher (odds ratio = 2.22 (95% CI = 0.79-6.26) in those with ST-segment-elevation AMI, compared to those with non-ST-segment-elevation AMI (odds ratio = 1.45 (95% CI = 0.81-2.57); early VT was not associated with rehospitalization in patients with either AMI subtype. No significant association was present between the occurrence of VT and CVD-related rehospitalization.

Conclusions

Patients who develop late VT may experience a higher risk of 30-day rehospitalization following hospital discharge for AMI, especially among those with ST-segment-elevation AMI. Larger studies are needed to confirm our findings.

Icariin improves cardiac function and remodeling via the TGF-β1/Smad signaling pathway in rats following myocardial infarction

BACKGROUND

Postinfarction cardiac remodeling presents a compensatory mechanism aimed at mitigating congestive heart failure. It is distinguished by progressive dilatation and hypertrophy of the ventricular chambers, fibrotic alterations, and prolonged apoptosis of cardiomyocytes. The primary objective of this study was to assess the effects of icariin on myocardial fibrosis and ventricular remodeling in rats subjected to myocardial infarction (MI).

METHODS

Male Sprague‒Dawley (SD) rats were subjected to randomization and subsequently divided into distinct groups: the control group, the sham group (undergoing sham operation), the MI group (experiencing ligation of the left anterior descending artery), and the icariin group. Within the icariin group, rats were further categorized into three different dose groups based on the administered icariin dosage: the MI30 group (30 mg/kg/day), the MI60 group (60 mg/kg/day), and the MI120 group (120 mg/kg/day). Cardiac function evaluation was carried out using echocardiography. Histological examinations, including hematoxylin and eosin (HE) staining, Masson staining, and immunohistochemistry studies, were conducted 90 days after the occurrence of MI. Additionally, Western blotting was employed to assess TGF-β1, p-Smad2, and p-Smad3 levels.

RESULTS

The administration of icariin revealed a noteworthy enhancement in cardiac function among rats afflicted with left anterior descending coronary artery (LAD) ligation. In comparison to the icariin groups, the MI group exhibited reduced EF and FS, along with elevated LVEDD and LVESD. Furthermore, the cardiac fibrosis levels in the MI group rats exhibited a considerable increase compared to those in the icariin group. Notably, the levels of Collagen I, Collagen III, MMP2, and MMP9 were significantly higher in the MI group than in the icariin group, with evident distinctions. Moreover, the expression levels of TGF-β, IL-13, p-Smad2, and p-Smad3 were notably upregulated in the MI group compared to the icariin group.

CONCLUSIONS

In an experimental rat model of MI, the administration of icariin resulted in the amelioration of both cardiac function and remodeling processes, operating through the intricate TGF-β1/Smad signaling pathway.