Safety and utility of mechanical circulatory support in patients with acute myocardial infarction complicated by cardiogenic shock: A systematic review and meta-analysis.

BACKGROUND: Acute myocardial infarction complicated by cardiogenic shock (AMI-CS) is a major cause of morbidity and mortality. Although mechanical circulatory support (MCS) is an increasingly utilized therapeutic option in AMI-CS, studies evaluating the efficacy and safety of different forms of MCS have yielded conflicting results. This systematic review and meta-analysis aims to evaluate the safety and efficacy of different forms of MCS. METHODS: A database search was performed for studies reporting on the association of different forms of MCS with clinical outcomes in patients with AMI-CS. The primary efficacy endpoints were short term (≤30 days) and long term (>30 days) all-cause mortality. Secondary efficacy endpoints included recurrent AMI, cardiovascular (CV) mortality, device-related limb complications, moderate to severe bleeding events, and cerebrovascular accidents (CVA). RESULTS: 2752 patients with AMI-CS met inclusion criteria. Results were available comparing ECMO to other MCS or medical therapy alone, comparing IABP to medical therapy alone, and comparing pLVAD to IABP. Use of ECMO was not associated with lower risk of 30-day or long-term mortality compared to pVAD or standard medical therapy with or without IABP placement but was associated with higher risk of device-related limb complications and moderate to severe bleeding compared to pVAD. IABP use was not associated with a lower risk of 30 day or long-term mortality but was associated with higher risk of recurrent AMI and moderate to severe bleeding compared to medical therapy. Compared to IABP, pVAD use was associated with lower risk of CV mortality but not recurrent AMI. pVAD was associated with a higher risk of device-related limb complications and moderate to severe bleeding compared to IABP use. CONCLUSION: Use of ECMO or IABP in patients with AMI-CS is not associated with significant improvement in mortality. pVAD is associated with a lower risk of CV mortality. All MCS types are associated with increased risk of complications. Additional high-quality studies are needed to determine the optimal MCS therapy for patients with AMI-CS.

Outcomes and Medical Therapy in Myocardial Infarction With Nonobstructive Coronary Arteries: A Systematic Review and Meta-Analysis.

Myocardial infarction with nonobstructive coronary arteries (MINOCAs) is a disease that has been poorly characterized with unclear clinical and therapeutic outcomes. The association of medical therapy with cardiovascular outcomes in patients with MINOCA has been inadequately assessed. The purpose of this meta-analysis is to evaluate the association of MINOCA at risk of adverse cardiovascular outcomes as compared with myocardial infarction with coronary artery disease (MICAD) and the efficacy of medical therapy in reducing the risk of adverse outcomes. A literature search was conducted for studies reporting on the association of MINOCA at risk of adverse outcomes as compared with MICAD. A literature search was also conducted for studies reporting on the association of medical therapy at risk of adverse outcomes in patients with MINOCA. A total of 29 studies with 893,134 participants met inclusion criteria comparing MINOCA to MICAD. Patients with MINOCA had a significantly lower risk of adverse outcomes as compared with MICAD. Nine studies with 27,731 MINOCA patients met inclusion criteria for evaluating the utility of medical therapy. Medical therapy did not significantly reduce risk of MACE; however, there was a trend toward lower risk in patients treated with ß blockers. In conclusion, our results suggest that MINOCA is associated with a lower risk of in-hospital and long-term adverse outcomes compared with MICAD. Standard medical therapy is not associated with a lower risk of adverse cardiovascular outcomes in patients with MINOCA. Additional high-quality studies are required to evaluate the utility of specific medication classes for the treatment of specific etiologies of MINOCA.

Matrix metalloproteinase inhibition with tetracyclines for the treatment of coronary artery disease.

Coronary artery disease is caused by atherosclerosis - a progressive arterial inflammatory disease that is responsible for significant global mortality and morbidity through the development of the acute coronary syndromes: sudden cardiac death, acute myocardial infarction and unstable angina. These clinical entities share a common pathophysiology: rupture of atherosclerotic plaque resulting in abrupt complete or partial thrombotic obstruction of coronary blood flow. Matrix metalloproteinases (MMP), through their central role in tissue remodeling and inflammation, are secreted by inflammatory cells of the atherosclerotic plaque and are capable of degrading all the extracellular matrix components of the fibrous cap that separates the atherosclerotic lesion from blood flow in the arterial lumen. Plaque rupture occurs when the circumferential tensile stresses in the artery overwhelm the structural integrity of the progressively degraded, thinned and weakened fibrous cap of the atherosclerotic lesion. Tetracyclines inhibit MMPs through their ability to chelate zinc. Subantimicrobial doses of doxycycline have been shown to reduce inflammation and inhibit MMP activity in patients with coronary artery disease. Further investigation is warranted to assess the potential clinical risks and benefits of MMP inhibition with tetracyclines or other agents in the treatment of coronary artery disease.

Heart failure with normal ejection fraction: consideration of mechanisms other than diastolic dysfunction.

More than half of patients with heart failure (HF) have a normal ejection fraction (EF). These patients are typically elderly, are predominantly female, and have a high incidence of multiple comorbid conditions associated with development of ventricular hypertrophy and/or interstitial fibrosis. Thus, the cause of HF has been attributed to diastolic dysfunction. However, the same comorbidities may also impact myocardial systolic, ventricular, vascular, renal, and extracardiovascular properties in ways that can also contribute to symptoms of HF by way of mechanisms not related to diastolic dysfunction. Accordingly, the descriptive term HF with normal EF has been suggested as an alternative to the mechanistic term diastolic HF. In this article, we review the current understanding of nondiastolic mechanisms that may contribute to the HF with normal EF syndrome to highlight potential pathways for research that may lead to new targets for therapy.

The impact of previous revascularization on clinical outcomes in patients undergoing primary percutaneous coronary intervention.

While the impact of prior coronary artery bypass graft surgery (CABG) on in-hospital outcomes in patients with ST-elevation myocardial infarction (STEMI) has been described, data are limited on patients with prior percutaneous coronary intervention (PCI) undergoing primary PCI in the setting of an STEMI. The aim of the present study was to assess the effect of previous revascularization on in-hospital outcomes in STEMI patients undergoing primary PCI. Between January 2004 and December 2007, a total of 1649 patients underwent primary PCI for STEMI at four New York State hospitals. Baseline clinical and angiographic characteristics and in-hospital outcomes were prospectively collected as part of the New York State PCI Reporting System (PCIRS). Patients with prior surgical or percutaneous coronary revascularization were compared to those without prior coronary revascularization. Of the 1649 patients presenting with STEMI, a total of 93 (5.6%) had prior CABG, 258 (15.7%) had prior PCI, and 1298 (78.7%) had no history of prior coronary revascularization. Patients with prior CABG were significantly older and had higher rates of peripheral vascular disease, diabetes mellitus, congestive heart failure, and prior stroke. Additionally, compared with those patients with a history of prior PCI as well as those without prior coronary revascularization, patients with previous CABG had more left main interventions (24% vs 2% and 2%; P<.001), but were less often treated with drug-eluting stents (47% vs 61% and 72%; P<.001). Despite a low incidence of adverse in-hospital events, prior CABG was associated with higher all-cause in-hospital mortality (6.5% vs 2.2%; P=.012), and as a result, higher overall MACE (6.5% vs 2.7%; P=.039). By multivariate analysis, prior CABG (odds ratio, 3.40; 95% confidence interval, 1.15-10.00) was independently associated with in-hospital mortality. In contrast, patients with prior PCI had similar rates of MACE (4.3% vs 2.7%; P=.18) and in-hospital mortality (3.1% vs 2.2%; P=.4) when compared to the de novo population. Patients with a prior history of CABG, but not prior PCI, undergoing primary PCI in the setting of STEMI have significantly worse in-hospital outcomes when compared with patients who had no prior history of coronary artery revascularization. Thus, only prior surgical - and not percutaneous - revascularization should be considered a significant risk factor in the setting of primary PCI.

Pregnancy in patients with pre-existing cardiomyopathies.

To varying extents, women with pre-existing cardiomyopathies have a limited cardiovascular reserve. The hemodynamic challenges of pregnancy, labor, and delivery pose unique risks to this group of patients, which can result in clinical decompensation with overt heart failure, arrhythmias, and rarely, maternal death. A multidisciplinary team approach and a controlled delivery are crucial to adequate management of patients with underlying heart disease. Pre-conception planning and risk assessment are essential, and proper counseling should be offered to expectant mothers with regard to both the risks that pregnancy poses and the implications for future offspring. In this article, we will review the hemodynamic stressors that pregnancy places upon women with pre-existing cardiomyopathies and risk assessment and discuss what evidence exists with regard to the management of 2 forms of cardiomyopathy during pregnancy, labor, and delivery: dilated and hypertrophic cardiomyopathy.