Reperfusion therapy reduces the risk of myocardial rupture complicating ST-elevation myocardial infarction

Post-Myocardial Infarction (MI) Left Ventricular Free Wall Rupture Managed Conservatively

Left ventricular free wall rupture (LVFWR) is an uncommon but often fatal complication of acute myocardial infarction. LVFWR is managed with hemodynamic stabilization and is typically followed by surgical intervention with varying approaches depending on the type of LVFWR. A 78-year-old male with a history of coronary artery bypass graft (CABG) was admitted with ST-segment elevation myocardial infarction. Left heart catheterization showed complete occlusion of the saphenous vein graft to the 1st obtuse marginal artery. The patient was not a candidate for percutaneous coronary intervention or CABG. The patient later developed atrial fibrillation with a rapid ventricular response which was managed with beta blockers. Computed tomography pulmonary angiogram was done to rule out pulmonary embolus; however, it demonstrated findings of a lateral LVFWR. The patient was deemed a poor surgical candidate for cardiothoracic surgery, and the LVFWR was managed conservatively with metoprolol succinate and bed rest. He later required amiodarone and direct current cardioversion due to the recurrence of atrial fibrillation. Two months following the LVFWR, the patient remained stable with no apparent complications. In a certain subset of LVFWR patients, surgical management may not be possible given patient anatomy and other high-risk factors. In these cases, conservative management with bed rest and beta blockers and treatment of ventricular and atrial arrhythmias may be a viable therapeutic option.

A rare case of concurrent left ventricular aneurysm and ventricular septal rupture complicating an inferior myocardial infarction: a case report

Complications following acute myocardial infarction (MI) such as ventricular septal rupture (VSR) and left ventricular (LV) aneurysm are rare and can be dreadful. Their simultaneous presence in the same patient is extremely rare. We aimed to present a rare case of concomitant association of ventricular aneurysm and VSR complicating an inferior myocardial infarction. We report the unusual case of Mr. A. D, a 63-year-old, active smoker, with a history of diabetes mellitus and hypertension, admitted for the management of inferior MI within 6 days. The MI was complicated by an LV aneurysm in the inferoposterior and the inferoseptal walls associated with a VSR in the inferoseptal wall. The patient had only signs of right heart failure on admission. This observation illustrates on the one hand the rarity of the association of VSR and LV aneurysm after an inferior myocardial infarction, and on the other hand the possibility of founding them at an early stage of MI without any signs of cardiogenic shock.

Don't go breakin' my heart: cardioprotective alterations to the mechanical and structural properties of reperfused myocardium during post-infarction inflammation

Myocardial infarctions (MIs) kickstart an intense inflammatory response resulting in extracellular matrix (ECM) degradation, wall thinning, and chamber dilation that leaves the heart susceptible to rupture. Reperfusion therapy is one of the most effective strategies for limiting adverse effects of MIs, but is a challenge to administer in a timely manner. Late reperfusion therapy (LRT; 3 + hours post-MI) does not limit infarct size, but does reduce incidences of post-MI rupture and improves long-term patient outcomes. Foundational studies employing LRT in the mid-twentieth century revealed beneficial reductions in infarct expansion, aneurysm formation, and left ventricle dysfunction. The mechanism by which LRT acts, however, is undefined. Structural analyses, relying largely on one-dimensional estimates of ECM composition, have found few differences in collagen content between LRT and permanently occluded animal models when using homogeneous samples from infarct cores. Uniaxial testing, on the other hand, revealed slight reductions in stiffness early in inflammation, followed soon after by an enhanced resistance to failure for cases of LRT. The use of one-dimensional estimates of ECM organization and gross mechanical function have resulted in a poor understanding of the infarct's spatially variable mechanical and structural anisotropy. To resolve these gaps in literature, future work employing full-field mechanical, structural, and cellular analyses is needed to better define the spatiotemporal post-MI alterations occurring during the inflammatory phase of healing and how they are impacted following reperfusion therapy. In turn, these studies may reveal how LRT affects the likelihood of rupture and inspire novel approaches to guide scar formation.

Acute Cardiac Emergencies

Acute cardiac emergencies are life threatening. The initial responses to acute cardiac emergencies must be rapid, efficient, skillful, and well-planned. The goal of this article is to provide information that can be used to facilitate the prompt recognition and treatment of the most common acute cardiac emergencies.

Increased incidence of postmyocardial infarction ventricular septal defects during Covid-19 pandemic: A case series

INTRODUCTION

Ventricular septal defect (VSD) is one of the mechanical complications of acute myocardial infarction (MI), whose incidence has been decreasing throughout the years because of the emergence of different reperfusion therapy strategies.

METHODS

We present a series of seven patients who underwent surgery for post-MI VSD repair in our institution in the period between March 2020 and June 2021.

DISCUSSION

During the recent SARS-COV2 pandemic, time to hospital admission increased due to patients being overcautious out of fear of exposing themselves to COVID-19. The increased time to hospital admission, with associated late reperfusion therapy and delayed PCI, is closely related to an augmented incidence of post-myocardial infarction mechanical complications such as ventricular septal defects. For this reason, we witnessed an increase in the incidence of post-MI VSD.

CONCLUSION

Fear of exposure to SARS-COV2 in the medical environment was a major source of concern for all our patients. The target of hospital policy should be to reassure patients of freedom from COVID in the emergency department and cardiac wards in order to prevent such dreadful complications.

PPARγ Mediates the Cardioprotective Roles of Danlou Tablet After Acute Myocardial Ischemia-Reperfusion Injury

Ischemic heart disease is one of the biggest threats to human life in the world. Reperfusion therapy is an effective strategy to reduce infarct size and ischemic injury. However, reperfusion process may cause secondary myocardial injury which is defined as ischemia-reperfusion injury (IRI). Exploring potential therapeutic strategy to attenuate IRI is extremely important. Danlou tablet (Dan), a Chinese herbal compound consisting of ten herbs, has been identified to be protective for the heart. However, the mechanism of Dan-induced cardioprotection after acute reperfusion was unelucidated. In this study, to investigate the role and mechanism of Dan in myocardial IRI, we performed acute IRI modeling in mice and oxygen-glucose deprivation–reperfusion (OGD/R)-induced apoptosis in primary neonatal rat cardiomyocytes (NRCMs). We found that Dan had protective effect against acute IRI in mice, as evidenced by reduced infarct size, TUNEL-positive cardiomyocytes (CMs), and Bax/Bcl2 ratio and cleaved-caspase 3/caspase 3 ratio in vivo. Meanwhile, Dan inhibited OGD/R-induced apoptosis of NRCMs in vitro. Mechanistically, Dan could activate proliferator-activated receptor gamma (PPARγ) in both IRI hearts and OGD/R-stressed NRCMs, while inhibition of PPARγ attenuated the protective effect of Dan against IRI in vivo and OGD/R-induced CM apoptosis in vitro. These data reveal that Dan attenuates acute myocardial IRI and CM apoptosis through activating PPARγ. Our findings may extend the knowledge of Chinese medicine and provide potential strategy for the precise treatment of ischemic heart diseases.

Concomitant ventricular septal rupture and interventricular septal aneurysm in neglected inferior myocardial infarction misdiagnosed with congenital ventricular septal defect: A case report

This study emphasizes that VSD should not be immediately diagnosed as a congenital disorder; instead, regional wall motion abnormalities in the left ventricle should also be taken into account since it may result from mechanical complications of neglected myocardial infarction.

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

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.

Dynamic Interstitial Cell Response during Myocardial Infarction Predicts Resilience to Rupture in Genetically Diverse Mice

Cardiac ischemia leads to the loss of myocardial tissue and the activation of a repair process that culminates in the formation of a scar whose structural characteristics dictate propensity to favorable healing or detrimental cardiac wall rupture. To elucidate the cellular processes underlying scar formation, here we perform unbiased single-cell mRNA sequencing of interstitial cells isolated from infarcted mouse hearts carrying a genetic tracer that labels epicardial-derived cells. Sixteen interstitial cell clusters are revealed, five of which were of epicardial origin. Focusing on stromal cells, we define 11 sub-clusters, including diverse cell states of epicardial- and endocardial-derived fibroblasts. Comparing transcript profiles from post-infarction hearts in C57BL/6J and 129S1/SvImJ inbred mice, which displays a marked divergence in the frequency of cardiac rupture, uncovers an early increase in activated myofibroblasts, enhanced collagen deposition, and persistent acute phase response in 129S1/SvImJ mouse hearts, defining a crucial time window of pathological remodeling that predicts disease outcome.

Low n-6/n-3 PUFA ratio improves inflammation and myocardial ischemic reperfusion injury

This study investigated the potential effect of n-6/n-3 polyunsaturated fatty acids (PUFA) on inflammation and myocardial ischemic reperfusion injury (MIRI) in rats, together with the underlying protective mechanisms, and screen out most effective ratio of n-6/n-3 within limits. The rats with pre-infarct treatment were distributed among 5 groups according to the n-6/n-3 ratio (36:1; 1:1, 5:1, 10:1, 50:1); for the post-infarct treatment, the rats were distributed among 6 groups, including the control group (36:1) which was subjected to a sham procedure; the model group (36:1); and 4 test groups (n-6/n-3 ratio: 1:1, 5:1, 10:1, 50:1). All of the rats were fed a purple perilla seed oil and safflower oil-based fatty emulsion. The serum levels of monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α were determined using enzyme-linked immunosorbent assay. Staining with triphenyl tetrazolium chloride, hematoxylin and eosin, or Masson's trichrome was performed for histological examination. Cardiomyocyte apoptosis was examined by TUNEL assay. Western blotting was performed to examine the expression levels of apoptosis-related proteins and signaling pathway proteins. Our data indicate that in both the pre-infarct treatment and post-infarct treatment, low ratios of n-6/n-3 PUFAs significantly inhibited the levels of serum inflammatory factors, the infarct size of MIRI rats, number of cardiomyocytes undergoing apoptosis, and the expression levels of caspase-3, Bcl-2, and Bax in the MIRI group. Thus a low ratio of n-6/n-3 PUFAs ameliorates inflammation and myocardial ischemic reperfusion injury.

Comparison of the risk of left ventricular free wall rupture in Taiwanese patients with ST-elevation acute myocardial infarction undergoing different reperfusion strategies: A medical record review study

Ventricular free wall rupture (VFWR) is the second most common cause of death in patients with acute ST-elevation myocardial infarction (STEMI). Nevertheless, few reports have investigated the factors, including different treatment strategies, associated with VFWR in Taiwanese patients. Therefore, the aim of this study was to compare the risk of VFWR in Taiwanese patients with acute STEMI who had received primary percutaneous coronary intervention (PCI), rescue PCI, scheduled PCI, thrombolytic therapy, and pharmacologic treatment. In this medical records review study, records of patients with acute STEMI admitted to a regional hospital in south Taiwan between March 1999 and October 2013 were screened. Multivariate stepwise logistic regression analysis was used to evaluate the association between the risk of VFWR and its independent factors. The overall incidence of VFWR among the 1545 patients with acute STEMI in this study was 1.6%. Compared with primary PCI, the risk of VFWR was significantly higher in patients who had received thrombolysis (adjusted odds ratio = 6.83, P = 0.003) or pharmacologic treatment alone (adjusted odds ratio = 3.68, P = 0.014). The risk of VFWR in patients receiving rescue PCI or scheduled PCI was not significantly different from that in patients receiving primary PCI. In addition, older age and Killip class >I were associated with an increased risk of VFWR in patients with acute STEMI, whereas the use of angiotensin-converting enzyme inhibitors was associated with a lower risk of VFWR. In conclusion, findings from this medical record review study provide support for the use of primary PCI, rescue PCI, and scheduled PCI over thrombolytic therapy and pharmacologic treatment in reducing the risk of VFWR in Taiwanese patients with acute STEMI.