Association of blood transfusion with increased mortality in myocardial infarction: a meta-analysis and diversity-adjusted study sequential analysis

BACKGROUND

The benefit of blood transfusion in patients with myocardial infarction is controversial, and a possibility of harm exists.

METHODS

A systematic search of studies published between January 1, 1966, and March 31, 2012, was conducted using MEDLINE, EMBASE, CINAHL, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials databases. English-language studies comparing blood transfusion with no blood transfusion or a liberal vs restricted blood transfusion strategy were identified. Two study authors independently reviewed 729 originally identified titles and abstracts and selected 10 for analysis. Study title, follow-up period, blood transfusion strategy, and mortality outcomes were extracted manually from all selected studies, and the quality of each study was assessed using the strengthening Meta-analysis of Observational Studies in Epidemiology checklist.

RESULTS

Studies of blood transfusion strategy in anemia associated with myocardial infarction were abstracted, as well as all-cause mortality rates at the longest available follow-up periods for the individual studies. Pooled effect estimates were calculated with random-effects models. Analyses of blood transfusion in myocardial infarction revealed increased all-cause mortality associated with a strategy of blood transfusion vs no blood transfusion during myocardial infarction (18.2% vs 10.2%) (risk ratio, 2.91; 95% CI, 2.46-3.44; P < .001), with a weighted absolute risk increase of 12% and a number needed to harm of 8 (95% CI, 6-17). Multivariate meta-regression revealed that blood transfusion was associated with a higher risk for mortality independent of baseline hemoglobin level, nadir hemoglobin level, and change in hemoglobin level during the hospital stay. Blood transfusion was also significantly associated with a higher risk for subsequent myocardial infarction (risk ratio, 2.04; 95% CI, 1.06-3.93; P = .03).

CONCLUSIONS

Blood transfusion or a liberal blood transfusion strategy compared with no blood transfusion or a restricted blood transfusion strategy is associated with higher all-cause mortality rates. A practice of routine or liberal blood transfusion in myocardial infarction should not be encouraged but requires investigation in a large trial with low risk for bias.

Benefits of β blockers in patients with heart failure and reduced ejection fraction: network meta-analysis

OBJECTIVE

To clarify whether any particular β blocker is superior in patients with heart failure and reduced ejection fraction or whether the benefits of these agents are mainly due to a class effect.

DESIGN

Systematic review and network meta-analysis of efficacy of different β blockers in heart failure.

DATA SOURCES

CINAHL(1982-2011), Cochrane Collaboration Central Register of Controlled Trials (-2011), Embase (1980-2011), Medline/PubMed (1966-2011), and Web of Science (1965-2011).

STUDY SELECTION

Randomized trials comparing β blockers with other β blockers or other treatments.

DATA EXTRACTION

The primary endpoint was all cause death at the longest available follow-up, assessed with odds ratios and Bayesian random effect 95% credible intervals, with independent extraction by observers.

RESULTS

21 trials were included, focusing on atenolol, bisoprolol, bucindolol, carvedilol, metoprolol, and nebivolol. As expected, in the overall analysis, β blockers provided credible mortality benefits in comparison with placebo or standard treatment after a median of 12 months (odds ratio 0.69, 0.56 to 0.80). However, no obvious differences were found when comparing the different β blockers head to head for the risk of death, sudden cardiac death, death due to pump failure, or drug discontinuation. Accordingly, improvements in left ventricular ejection fraction were also similar irrespective of the individual study drug.

CONCLUSION

The benefits of β blockers in patients with heart failure with reduced ejection fraction seem to be mainly due to a class effect, as no statistical evidence from current trials supports the superiority of any single agent over the others.

Extended thromboprophylaxis for medically ill patients with decreased mobility: does it improve outcomes?

BACKGROUND

Duration of thromboprophylaxis beyond hospital discharge for medically ill patients has been controversial. Therefore an evaluation was made of the evidence currently available.

METHODS

A search was made of the Pub Med, CENTRAL and EMBASE databases for randomized controlled trials from 1966 through to 2011. Interventions included thromboprophylaxis administered over an extended period in patients hospitalized for acute medical illness with decreased level of mobility. No differentiation was made for the medication used for individual studies. The comparator included standard medical therapy and/or placebo. The efficacy outcomes assessed were a composite of asymptomatic and symptomatic deep vein thromboses (DVT), pulmonary emboli (PE) and venous thromboembolism (VTE)-related deaths in the intervention group vs. the comparator group, as well as the safety outcomes evaluated with rates of bleeding events at the end of at least 30 days of follow-up. The methodological quality of the studies was assessed, as was publication bias. Event rates were compared using a forest plot of relative risk (RR; 95% confidence interval (CI)) using a random effects model (Mantel-Haenszel) between the active thromboprophylaxis and controls. Statistical analysis was carried out with Review Manager V5.1.

RESULTS

Three recent studies were included. Extended duration thromboprophylaxis reduced the combined composite event rate, RR 0.75 (0.64, 0.88). However, individual clinical endpoints were not significantly improved with extended prophylaxis: asymptomatic proximal DVT, RR 0.85 (0.68, 1.05); symptomatic DVT, RR 0.44 (0.19, 1.00); symptomatic non-fatal PE, RR 0.80 (0.43, 1.48); VTE-related death, RR 0.64 (0.38, 1.10). However, bleeding events were far more prevalent with extended thromboprophylaxis with major bleeds, RR 2.68 (1.78, 4.05), with a number needed to harm of 194.

CONCLUSION

Currently available evidence does not indicate that routine administration of post-discharge prophylaxis will be beneficial to the patients admitted for medical illness.

Abstract 100: Electrocardiographic Changes in Patients ≥ 100 Years Of Age

Background: Centenarian population in the United States is increasing, and cardiovascular disease is the most common cause of death in this group of patients. We report electrocardiographic changes in a group of 124 centenarians.

METHODS: We included ECGs of 124 patients aged 100 to 112 years (mean age 102 years), who were seen either on office visits or on recent admission to the hospital. ECGs were analyzed by 2 different investigators.

Results: Women were at least 2 times men in number (31% vs 69%, 39 vs 85 of 124); thus women outlived men in the centenarian group. 58% (72 of 124) patients had normal sinus rhythm and only 7 of 124 patients (6%, all women) had normal ECGs. The most common electrocardiographic abnormalities were: left-axis deviation (29%, 36 of 124), atrial fibrillation (AF) (27%, 34 of 124), right bundle branch block (15%, 18 of 124), left anterior fascicular block (14%, 17 of 124), left ventricular hypertrophy (14%, 17 of 124), first-degree atrioventricular (AV) block (13%, 16 of 124), nonspecific ST-T changes (13%, 16 of 124), premature atrial complexes (13%, 16 of 124), premature ventricular complexes (10%, 13 of 124) and pacemaker rhythm (10%, 13 of 124). Almost all Q waves were suggestive of old inferior wall infarcts and were present in 8% (10 of 124) of patients. Only 3 centenarians had QTc prolongation.

Conclusion: Fewer men live long enough to reach 100 years of age, consistent with higher incidence of ischemic heart disease in men. Centenarians had higher incidence of AF indicative of increased incidence of AF with age. Increased incidence of left-axis deviation, left anterior fascicular block and left ventricular hypertrophy in centenarians can be attributed to age related cardiac hypertrophy and prevalence of hypertension. Also higher prevalence of conduction disturbances including AV block and bundle branch block indicates that a degenerative conduction system disorder may progress with advancing age. The finding of pacemaker rhythm in a few subjects confirms that pacemaker implantation may allow some patients to reach extreme longevity. Overall centenarians represent a model of successful aging and have satisfactory electrocardiographic framework that reflects a good cardiac function, contributing to attainment of extreme longevity.

Meta-analysis of cardiovascular outcomes with dronedarone in patients with atrial fibrillation or heart failure

Dronedarone is a benzofuran derivative approved by the Food and Drug Administration to decrease the risk of cardiovascular hospitalization in patients with paroxysmal or persistent atrial fibrillation (AF) and associated cardiovascular risk factors who are in sinus rhythm or will undergo cardioversion. There has been recent evidence to suggest that dronedarone may not have a favorable safety profile. We decided to evaluate all available evidence on the cardiovascular safety of this drug. A systematic search was made of the PubMed, CENTRAL, and EMBASE databases for randomized controlled trials from 1966 through 2011 comparing dronedarone to comparators in AF/heart failure. Intervention was dronedarone for AF for some studies and heart failure for others. Comparators included standard medical therapy and/or placebo and amiodarone for 1 study. Outcomes assessed were all-cause mortality, cardiovascular mortality, ventricular arrhythmias, embolic events, acute coronary syndrome, heart failure exacerbations, and hospitalization rates in the intervention versus comparator group at the end of ≥ 3 months of follow up with abstraction of data by 1 author. Seven randomized controlled trials were included in our analysis. Dronedarone use was associated with a trend toward worse all-cause and cardiovascular mortalities and increased heart failure exacerbations. It also showed numerically higher event rates for all other outcome events except acute coronary syndrome. Our pooled analysis showed increased all-cause and cardiovascular mortalities and increased heart failure exacerbations with use of dronedarone across a wide spectrum of populations. In conclusion, we recommend exercising caution using dronedarone, especially in patients with cardiovascular risk factors.

Effectiveness of Cardiac Resynchronization Therapy by QRS Morphology in the Multicenter Automatic Defibrillator Implantation Trial–Cardiac Resynchronization Therapy (MADIT-CRT)

Background—

This study aimed to determine whether QRS morphology identifies patients who benefit from cardiac resynchronization therapy with a defibrillator (CRT-D) and whether it influences the risk of primary and secondary end points in patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial–Cardiac Resynchronization Therapy (MADIT-CRT) trial.

Methods and Results—

Baseline 12-lead ECGs were evaluated with regard to QRS morphology. Heart failure event or death was the primary end point of the trial. Death, heart failure event, ventricular tachycardia, and ventricular fibrillation were secondary end points. Among 1817 patients with available sinus rhythm ECGs at baseline, there were 1281 (70%) with left bundle-branch block (LBBB), 228 (13%) with right bundle-branch block, and 308 (17%) with nonspecific intraventricular conduction disturbances. The latter 2 groups were defined as non-LBBB groups. Hazard ratios for the primary end point for comparisons of CRT-D patients versus patients who only received an implantable cardioverter defibrillator (ICD) were significantly ( P <0.001) lower in LBBB patients (0.47; P <0.001) than in non-LBBB patients (1.24; P =0.257). The risk of ventricular tachycardia, ventricular fibrillation, or death was decreased significantly in CRT-D patients with LBBB but not in non-LBBB patients. Echocardiographic parameters showed significantly ( P <0.001) greater reduction in left ventricular volumes and increase in ejection fraction with CRT-D in LBBB than in non-LBBB patients.

Conclusions—

Heart failure patients with New York Heart Association class I or II and ejection fraction ≤30% and LBBB derive substantial clinical benefit from CRT-D: a reduction in heart failure progression and a reduction in the risk of ventricular tachyarrhythmias. No clinical benefit was observed in patients with a non-LBBB QRS pattern (right bundle-branch block or intraventricular conduction disturbances).

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00180271.

Elevated troponin level is not synonymous with myocardial infarction

BACKGROUND

Elevated troponin I in the absence of angiographically visible coronary lesions is seen in up to 10-15% of those undergoing angiography for suspected coronary artery disease. This study aims to elucidate the etiology of elevated cardiac troponin I in patients with normal coronary arteries on angiography.

METHODS

We identified 1551 (8.6%) patients with normal coronary arteries from our catheterization database of 17,950 patients from Jan 2000 to Jun 2004. Elevated troponin I levels were found in 217 (14%) of 1551 patients with normal coronary arteries. Of these 217 patients, 73 surgical patients were excluded, and the remaining 144 patients formed the study population. The study population was compared with age and gender matched patients with myocardial infarction and coronary artery disease (Group II).

RESULTS

The patients with elevated cardiac troponin I (cTnI) with normal coronary arteries had significantly lower prevalence of atherosclerotic risk factors and significantly higher left ventricular ejection fractions. The cTnI in patients with normal coronary arteries was elevated due to a number of causes including tachycardia, myocarditis, pericarditis, severe aortic stenosis, gastrointestinal bleeding, sepsis, left ventricular hypertrophy, severe congestive heart failure, cerebrovascular accident, electrical trauma, myocardial contusion, hypertensive emergency, myocardial bridging, pulmonary embolism, diabetic ketoacidosis, chronic obstructive pulmonary disease exacerbation and coronary spasm.

CONCLUSIONS

Cardiac troponin I could be elevated in a number of conditions, apart from acute myocardial infarction, and could reflect myonecrosis. Acute myocardial infarction is a clinical diagnosis as the laboratory is an aide to, not a replacement for, informed decision making.

Prediction of left main coronary artery obstruction by 12-lead electrocardiography: ST segment deviation in lead V6 greater than or equal to ST segment deviation in lead V1

BACKGROUND

Acute coronary syndrome (ACS) resulting from culprit lesion in left main coronary artery (LMCA) can cause rapid hemodynamic deterioration. It is important to identify these patients early to facilitate timely revascularization. ST segment elevation in aVR greater than or equal to V(1) (aVR-V(1)>or= 0) has been suggested as a sensitive predictor of LMCA disease. As a result of balanced forces, we hypothesized that ST deviation in V(6) greater than or equal to ST deviation in V(1) (V(6)-V(1)>or= 0) might be a good determinant of LMCA disease.

METHODS

We compared admission 12-lead ECGs of ACS resulting from culprit LMCA lesion (n = 75, group I) with ACS resulting from culprit left anterior descending lesion (n = 81, group II). Group I was selected over a period of 10 years. We compared V(6)-V(1)>or= 0 to aVR-V(1)>or= 0 in both groups. We also looked at ratios of ST deviations in V(6),V(1) (V(6)/V(1)>or= 1) and aVR,V(1) (aVR/V(1)>or= 1) in patients where ST segment in V(1) was not isoelectric (group I = 54 and group II = 55).

RESULTS

ST deviation in V(6) was significantly greater in group I as compared to group II (P < 0.001). The reliabilities of V(6)-V(1)>or= 0, V(6)/V(1)>or= 1, aVR-V(1)>or= 0, and aVR/V(1)>or= 1 in predicting LMCA disease were determined.

CONCLUSION

This is the largest series of ECG analysis on ACS resulting from culprit LMCA lesion. V(6)-V(1)>or= 0 and V(6)/V(1)>or= 1 were more sensitive in predicting LMCA as culprit vessel in comparison to previously reported greater ST segment elevation in aVR than V(1).

Atherosclerotic risk genotypes and recurrent coronary events after myocardial infarction

The association of a group of prespecified atherosclerotic risk genotypes with recurrent coronary events (coronary-related death, nonfatal myocardial infarction, or unstable angina) was investigated in a cohort of 1,008 patients after infarction during an average follow-up of 28 months. We used a carrier-ship approach with time-dependent survivorship analysis to evaluate the average risk of each carried genotype. Contrary to expectation, the hazard ratio for recurrent coronary events per carried versus noncarried genotype was 0.89 (95% confidence interval 0.80 to 0.99, p = 0.03) after adjustment for relevant genetic, clinical, and environmental covariates. This hazard ratio, derived from the 7 prespecified genotypes, indicated an average 11% reduction in the risk of recurrent coronary events per carried versus noncarried genotype. At 1 year after hospital discharge, the cumulative probability of recurrent coronary events was 26% in those who carried < or =1, 20% for those with 2 to 4, and 13% for those with > or =5 of these genotypes (p = 0.02). This unexpected risk reversal is a likely consequence of changes in the mix of risk factors in pre- and postinfarction populations. In conclusion, this under appreciated, population-based, risk-reversal phenomenon may explain the inconsistent associations of genetic risk factors with outcome events in previous reports involving coronary populations with different risk attributes.

20-Year Follow-up of a Patient with Coronary Artery Spasm

The authors present a 20-year follow-up of a patient with well-documented coronary artery spasm, who initially presented with syncope. The patient had excellent response to calcium channel antagonists and long-acting nitrates.

Giving IV and Oral Amiodarone Perioperatively for the Prevention of Postoperative Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Surgery

PURPOSES

We studied the use of perioperative IV and oral administration of amiodarone for the prevention of postoperative atrial fibrillation in patients undergoing coronary artery bypass graft surgery (CABG).

BACKGROUND

In the United States, > 500,000 patients undergo CABG each year. Numerous studies to date have suggested that postoperative atrial fibrillation occurs in 30 to 50% of patients, leading to significant morbidity, including hypotension, heart failure, thromboembolic complications, prolonged hospital stay, and increased hospital costs. The objective of this study was to assess the use of IV amiodarone in combination with oral amiodarone to reduce the incidence of postoperative atrial fibrillation.

METHOD

From January 1999 to October 1999, 51 patients scheduled for CABG were randomly selected for participation in the amiodarone administration trial. IV amiodarone, 0.73 mg/min, was administered on call to the operating room for 48 h, followed by oral amiodarone, 400 mg q12h, for the next 3 days. The amiodarone group was case-control matched to the incidence of postoperative atrial fibrillation in 92 patients undergoing CABG using conventional medical therapy during the same period. The primary end point of this study was the incidence of postoperative atrial fibrillation, length of hospital stay, and hospital costs, compared to the control group undergoing CABG during the same time.

RESULTS

Atrial fibrillation occurred in 3 of 51 patients (5.88%) in the amiodarone group, compared to 24 of 92 patients (26.08%) in the control group. Length of hospital stay in the amiodarone group was less than in the control group (5.3 days vs 6.7 days), with a trend toward decrease in hospital costs.

CONCLUSION

The administration of IV amiodarone in conjunction with oral amiodarone for a total dose of 4,500 mg over 5 days appears to be a hemodynamically well-tolerated, safe, and effective treatment in decreasing the incidence of postoperative atrial fibrillation, shortening length of stay, and a trend toward lowering hospital costs, even in patients with significantly reduced left ventricular function (< 30%). A large multicenter study using IV and oral amiodarone should be pursued prior to deciding whether its use should become standard therapy in all patients undergoing CABG in order to decrease the incidence of postoperative atrial fibrillation.

Relationship Between Intermittent Claudication, Inflammation, Thrombosis, and Recurrent Cardiac Events Among Survivors of Myocardial Infarction

BACKGROUND

Among coronary disease patients, concomitant peripheral arterial disease is a potent risk factor for future cardiac events and mortality. We sought to determine clinical and biochemical markers that might better elucidate the relationship between coronary and peripheral arterial disease.

METHODS

Two months after an index myocardial infarction, 1045 patients provided detailed medical histories and underwent blood testing for selected hemostatic, lipid, and inflammatory markers. Patients were then followed up prospectively for a mean of 26 months.

RESULTS

Compared with individuals without intermittent claudication (n = 966), those with claudication (n = 78) (information was unavailable for 1 individual) were significantly older and demonstrated an increased frequency of diabetes mellitus, tobacco use, prior cardiac and cerebrovascular events, and depressed left ventricular function. Individuals with claudication were less likely to receive beta-blocker therapy after the index infarction. Individuals with claudication had evidence of enhanced procoagulant and proinflammatory states manifested by relative elevations in plasma fibrinogen, D-dimer, C-reactive protein, and serum amyloid A concentrations. During follow-up, the presence of claudication was associated with an independent 2-fold increase in the combined end point of death or nonfatal cardiac event (38.5% vs 17.8%, P =.001) and a 5-fold increase in cardiac mortality (19.2% vs 3.6%, P =.001). Patients with intermittent claudication who were not treated with beta-blockers had a significant 3-fold mortality excess relative to those receiving beta-blockers.

CONCLUSIONS

Following myocardial infarction, the added presence of intermittent claudication is associated with heightened procoagulant and proinflammatory states and an underuse of beta-blocker therapy and is a strong independent predictor of recurrent cardiovascular events.

Maternal arrhythmias of normal labor and delivery

Labor and delivery are associated with significant hemodynamic changes, as well as pain and anxiety, all of which could be fertile ground for arrhythmias. In order to establish whether cardiac arrhythmias occur more frequently during labor and delivery in healthy parturients and whether it clinically affects the mother or the newborn, 100 pregnant women admitted for delivery had Holter monitoring before, during, and up to 1 h postpartum. Our results show that, excluding sinus rhythm variations, only a slight majority of the study subjects had arrhythmia at all, while only 2% had more complex arrhythmias, none of which required any therapeutic intervention. We conclude that cardiac arrhythmias occurring during labor, delivery, and postpartum in the healthy parturient are no more frequent than in the general female population of the same age and are without clinical consequences for the mother and the newborn.