Culprit versus multivessel coronary intervention in ST-segment elevation myocardial infarction: a meta-analysis of randomized trials.

BACKGROUND: The 2015 American College of Cardiology/American Heart Association update on primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) recommended PCI of the non-infarct-related artery at the time of primary PCI (class IIb recommendation). Despite evidence supporting complete revascularization in STEMI, its benefit on mortality rates is uncertain. METHODS: We searched all available databases for randomized controlled trials comparing complete multivessel percutaneous coronary intervention (CMV PCI) with infarct-artery-only revascularization in patients with STEMI. Summary risk ratios and 95% confidence intervals (CIs) were calculated for both the efficacy and safety outcomes. RESULTS: Nine randomized controlled trials fulfilled the inclusion criteria, yielding 2991 patients. Follow-up periods ranged from 6 to 36 months. Compared with infarct-related artery-only PCI, CMV PCI was associated with significantly lower rates of major adverse cardiac events [relative risk (RR)=0.54, 95% CI=0.41-0.71; P<0.00001], cardiovascular mortality (RR=0.48, 95% CI=0.28-0.80; P=0.005), and repeat revascularization (RR=0.38, 95% CI=0.30-0.47; P<0.00001). Although, contrast-induced nephropathy and major bleed rates were comparable between both groups, CMV PCI failed to show any reduction in all-cause mortality (RR=0.75, 95% CI=0.53-1.07; P=0.11) and nonfatal myocardial infarction (RR=0.69, 95% CI=0.43-1.10; P=0.12). CONCLUSION: Our results suggest that in patients with STEMI and multivessel disease, complete revascularization is safe, and is associated with reduced risks of major adverse cardiac events and cardiac death along with a reduced need for repeat revascularization. However, it showed no beneficial effect on all-cause mortality and nonfatal myocardial infarction.

Type 2 versus type 1 myocardial infarction: a comparison of clinical characteristics and outcomes with a meta-analysis of observational studies.

BACKGROUND: Type 2 myocardial infarction (MI) is an imbalance between myocardial oxygen demand and supply, leading to myocardial ischemia. It is not due to plaque rupture, and is usually caused by a condition other than coronary artery disease (CAD). However, limited data are available comparing the prevalence of traditional coronary risk factors and mortality between type 1 and type 2 MI. We hypothesize that type 2 MI carries a higher mortality than type 1. METHODS: We searched the databases of PubMed, EMBASE, CENTRAL, and MEDLINE for studies comparing type 1 MI with type 2 MI. The baseline variables were compared in each cohort. Summary risk ratios and 95% confidence intervals were calculated using the random effects model to compare mortality between the two groups. RESULTS: The included studies yielded 25,872 patients of whom 2,683 (10%) had type 2 MI. Compared to the type 1 cohort, the type 2 cohort had significantly higher inpatient (15% vs. 4.7%, P<0.00001), 30-day (17.6% vs. 5.3%, P<0.00001) and 1-yr mortality (27% vs. 13%, P<0.00001), as well as higher 30-day major adverse cardiovascular events (20% vs. 9%, P<0.0001). Operative stress (20%) was the most common trigger of type 2 MI, followed by sepsis (19%), arrhythmia (18.63%), heart failure (15%), and anemia (12%). CONCLUSIONS: Type 2 MI is a common entity and is more common in females, older age groups, and in patients with multiple comorbidities: it also tends to result in higher mortality.

Infarct related artery only versus complete revascularization in ST-segment elevation myocardial infarction and multi vessel disease: a meta-analysis.

BACKGROUND: The 2015 American College of Cardiology Foundation/American Heart Association (ACCF/AHA) focused update on primary percutaneous coronary intervention (PCI) for patients with ST-segment elevation myocardial infarction (STEMI) only gives a class II b (weak) indication for non-infarct artery intervention at the time of primary PCI. Recent randomized controlled trials, however, suggest strong evidence supporting complete revascularization. METHODS: A systematic search was conducted in PUBMED, MEDLINE, EMBASE and Cochrane central register for randomized controlled trials comparing complete versus infarct artery (IRA) only revascularization in patients with STEMI. A meta-analysis was performed using the data extracted from each study. Summary risk ratios (RR) and 95% confidence intervals (CI) were calculated for five outcomes. RESULTS: Six trials fulfilled the inclusion criteria yielding 1,792 patients. Follow up ranged from 6 months to 2.5 years. The incidence of major adverse cardiac events (MACE) was significantly lower in the complete revascularization group compared to the IRA only revascularization (13.8% vs. 25.1%, RR =0.51; 95% CI: 0.41-0.64, P<0.00001). It was attributed to significantly lower repeat revascularization rate in the complete revascularization group (8.2% vs. 18.9%, RR =0.41; 95% CI: 0.31-0.54, P<0.00001). This meta-analysis also showed a significant reduction in cardiovascular mortality (2.0% vs. 4.6%, RR =0.42; 95% CI: 0.24-0.74; P=0.003), non-fatal myocardial infarction (4.37% vs. 5.76%, RR =0.64; 95% CI: 0.34-1.20; P=0.16) and all-cause mortality rates [(4.6% vs. 6%), RR =0.75; 95% CI: 0.49-1.14, P=0.17] in the complete revascularization group, compared to the IRA revascularization group. CONCLUSIONS: In patients who present with STEMI, complete revascularization is associated with lower rates of MACE and cardiovascular deaths as compared to revascularization of the IRA alone. Even though the outcomes of all-cause mortality and nonfatal re-infarction rates were lower in the complete revascularization group, they were not significant.

Right ventricular failure predicted from right bundle branch block: cardiac magnetic resonance imaging validation.

BACKGROUND: Right ventricular (RV) failure has proven to be independently associated with adverse outcomes. Electrocardiographic parameters assessing RV function are largely unknown, making echocardiography the first line for RV function assessment. It is however, limited by geometrical assumptions and is inferior to cardiac magnetic resonance imaging (CMRI) which is widely regarded as the most accurate tool for assessing RV function. METHODS: We seek to determine the correlation of ECG parameters of right bundle branch block (RBBB) with RV ejection fraction (EF) and RV dimensions using the CMRI. QRS duration, R amplitude and R' duration were obtained from precordial lead V1; S duration and amplitude were obtained from lead I and AVL. RV systolic dysfunction was defined as RV EF <40%. RV systolic dysfunction group (mean EF of 24±10%) were compared with normal RV systolic function group which acted as control (mean EF of 48±8%). CMRI and ECG parameters were compared between the two groups. Rank correlations and scatter diagrams between individual CMRI parameters and ECG parameters were done using medcalc for windows, version 12.5. Sensitivity, specificity and area under the curve (AUC) were calculated. RESULTS: RV systolic dysfunction group was found to have larger RV end systolic volumes (90±42 vs. 59±40 mL, P=0.02). ECG evaluation of RV dysfunction group revealed longer R' duration (103±22 vs. 84±18 msec, P=0.005) as compared to the control group. The specificity of R' duration >100 msec to detect RV systolic dysfunction was found to be 93%. R' duration was found to have an inverse correlation with RV EF (r=-0.49, P=0.007). CONCLUSIONS: Larger RV end systolic volumes seen with RV dysfunction can affect the latter part of right bundle branch leading to prolonged R' duration. We here found prolonged R' duration in lead V1 to have a highly specific inverse correlation to RV systolic function. ECG can be used as an inexpensive tool for RV function assessment and should be used alongside echocardiography to evaluate RV dysfunction when CMRI is not available.

Fatal pulmonary embolism complicating a postoperative chylothorax despite adequate thromboprophylaxis.

Chylothorax is a recognized complication of intrathoracic surgery, but its occurrence after coronary artery bypass grafting (CABG) is very rare. We report a case of a fatal pulmonary embolism as a complication of chylothorax following CABG. The patient was an 82-year-old woman who presented with increasing chest pain 2 weeks after discharge after an uncomplicated CABG. A computerized tomography (CT) scan with contrast angiogram showed a left-sided pleural effusion and no concurrent pulmonary embolus. Analysis of the pleural effusion revealed a chylothorax, which was treated with chest tube drainage and total parenteral nutrition followed by an oral medium-chain fatty acid diet. The patient improved steadily but, on day 6, she developed acute hypoxemic respiratory failure and shock. A CT angiogram revealed a massive pulmonary embolus and, despite thrombolysis, the patient died. Autopsy confirmed an acute saddle embolus in the pulmonary trunk. The patient had received appropriate venous thromboembolism prophylaxis with subcutaneous unfractionated heparin during her hospital course. This is the first reported case of a fatal pulmonary embolism that occurred in the setting of a post-CABG chylothorax in adults. The occurrence of this complication despite unfractionated heparin thromboprophylaxis may suggest a role for other, more effective medications, such as low molecular weight heparin or fondaparinux in patients with chylothorax.