Cardiac rupture complicating acute myocardial infarction: the clinical features from an observational study and animal experiment

Abstract

Background: Cardiac rupture (CR) is a fatal complication of ST-elevation myocardial infarction (STEMI) with its incidence markedly declined in the recent decades. However, clinical features of CR patients now and the effect of reperfusion therapy to CR remain unclear. We investigated the clinical features of CR in STEMI patients and the effect of reperfusion therapy to CR in mice.

Methods: Two studies were conducted. In clinical study, data of 1456 STEMI patients admitted to the First Hospital, Xi'an Jiaotong University during 2015.12. ~ 2018.12. were analyzed. In experimental study, 83 male C57BL/6 mice were operated to induce MI. Of them, 39 mice were permanent MI (group-1), and remaining mice received reperfusion after 1 h ischemia (21 mice, group-2) or 4 h ischemia (23 mice, group-3). All operated mice were monitored up to day-10. Animals were inspected three times daily for the incidence of death and autopsy was done for all mice found died to determine the cause of death.

Results: CR was diagnosed in 40 patients: free-wall rupture in 17, ventricular septal rupture in 20, and combined locations in 3 cases. CR presented in 19 patients at admission and diagnosed in another 21 patients during 1 ~ 14 days post-STEMI, giving an in-hospital incidence of 1.4%. The mortality of CR patients was high during hospitalization accounting for 39% of total in-hospital death. By multivariate logistic regression analysis, older age, peak CK-MB and peak hs-CRP were independent predictors of CR post-STEMI. In mice with non-reperfused MI, 17 animals (43.6%) died of CR that occurred during 3-6 days post-MI. In MI mice received early or delayed reperfusion, all mice survived to the end of experiment except one mouse died of acute heart failure.

Conclusion: CR remains as a major cause of in-hospital death in STEMI patients. CR patients are characterized of being elderly, having larger infarct and more server inflammation. Experimentally, reperfusion post-MI prevented CR.

Keywords: Acute myocardial infarction; Cardiac rupture; Prognosis; Reperfusion; Risk factor; Sudden cardiac death.

Fig. 1

Representative transthoracic echocardiographic images from patients with cardiac rupture. a 2-D image revealed discontinuity of the left ventricular (LV) wall (white arrow) and pericardial effusion (red arrow). b Color Doppler image demonstrated shunting of blood flow from the LV to the pericardium (white arrow) and presence of pericardial effusion (red arrow). c ventricular septum discontinuity (white arrow) in 2-D image. d shunting of blood from the LV to the right ventricle (RV, red arrow) in Color Doppler image; LA = left atrium; RA = right atrium

Fig. 2

The times from symptom onset to cardiac rupture diagnosis

Fig. 3

Comparison of laboratory parameter between STEMI with or without cardiac rupture. CK-MB: creatine kinase-MB, hs-CRP: high sensitive C-reactive protein, FDP: fibrinogen degradation product, WBC: white blood cell. *P < 0.05 vs. STEMI without CR. Note: n = 11 in rupture group for peak CK-MB and peak hs-CRP

Fig. 4

Multivariate logistic regression analysis of risk factors and the incidence of cardiac rupture. CK-MB: creatine kinase-MB; hs-CRP: high sensitive C-reactive protein

Fig. 5

Survival curves of patients with cardiac rupture. a compared between in STEMI patients with and without CR. b compared between FWR group and VSR group. c compared between drug treatment only and life support, surgery and closure in CR. FWR: free wall rupture, VSR: ventricular septum rupture

Fig. 6

Effect of reperfusion on the incidence of CR and infarct size in mice. a Comparison of survival in mice with permanent coronary artery occlusion (Group-1, n = 36), or reperfusion following 1-h (Group-2, n = 19) or 4-h (Group 3, n = 21) ischemia. b influence of reperfusion on infarct size in relation to ischemic duration. Note that infarct size was significantly reduced by early (i.e. 1-h ischemia) but not delayed (4-h ischemia) reperfusion. Infarct size date are mean ± SEM. The group size was 6–8. *P < 0.01 vs. non-reperfused MI or 4-h IR group