Usefulness of either or both left and right bundle branch block at baseline or during follow-up for predicting death in patients following acute myocardial infarction

Acute myocardial infarction with right bundle branch block at presentation: Prevalence and mortality

AIMS

Right Bundle Branch Block (RBBB) has been reported in 5-11% of the acute myocardial infarctions (AMI), and it could be the only electrocardiographic abnormality in this group of patients. We investigated the mortality in patients with AMI and the presence of RBBB.

MATERIALS AND METHODS

A retrospective cohort study was conducted between January 2011 to December 2017 at a university hospital in Bogotá, Colombia. Records were obtained from all patients who presented at the emergency department with AMI; patients with early transfer and incomplete follow-up were excluded.

RESULTS

1015 patients were included, the mean age was 66 years, 67% of the patients were men, and 38% had STEMI. RBBB was documented in 8% of patients and LBBB in 4% of patients. In-hospital mortality was higher in the group of patients with RBBB vs. patients without RBBB (8.64% vs. 3.74%, p = 0.034). The percentage of patients with Killip ≥II classification was higher in patients with new RBBB vs. patients with old or unknown duration RBBB (23% vs. 13%, p = 0.216).

CONCLUSIONS

In patients with AMI, the presence of RBBB was associated with a statistically significant increase of in-hospital mortality.

Right bundle brunch block in patients with acute myocardial infarction is associated with a higher in-hospital arrhythmic risk and mortality, and a worse prognosis after discharge

INTRODUCTION

Recently, the presence of right bundle brunch block (RBBB) in patients with persistent ischaemic symptoms has been suggested as an indication for emergent coronary angiography.

OBJECTIVE

The aim of this study was to assess the prognostic impact of RBBB in patients with acute myocardial infarction (AMI) before the implementation of the recent recommendations.

METHODS

We retrospectively studied consecutive patients admitted with AMI between 2011 and 2013. Patients with left bundle brunch block, pacemaker, or nonspecific intraventricular conduction delay were excluded. Patients with RBBB were compared with those without RBBB. Clinical characteristics, in-hospital evolution, and major adverse cardiovascular events (MACE) during follow-up, defined as cardiovascular death, sustained ventricular arrhythmias, acute heart failure syndromes, recurrent myocardial infarction, or acute stroke, were analysed.

RESULTS

The analysis included 481 patients. Thirty two patients (6.7%) had RBBB. Patients with RBBB were older. During hospital admission, RBBB patients had a higher rate of sustained ventricular tachycardia and death. Survival curve analysis showed that patients with RBBB had a lower in-hospital survival rate (Log-rank, p = 0.004). After discharge, during a mean follow-up time of 24.3 ± 11.6 months, 53 patients (12%) died. Survival curve analysis showed a lower survival rate free of MACE for those patients with RBBB (Log-rank, p = 0.011). RBBB was independently associated with MACE occurrence (HR 2.17, 95% CI 1.07-4.43; p = 0.033), after adjusting for demographic data, coronary angiography findings, treatment performed, echocardiographic evaluation, and medical therapy.

CONCLUSION

Patients with RBBB had a higher rate of in-hospital mortality and arrhythmic events, and an increased risk of MACE during follow-up.

Pharmacological interventions for heart failure in people with chronic kidney disease

BACKGROUND

Approximately half of people with heart failure have chronic kidney disease (CKD). Pharmacological interventions for heart failure in people with CKD have the potential to reduce death (any cause) or hospitalisations for decompensated heart failure. However, these interventions are of uncertain benefit and may increase the risk of harm, such as hypotension and electrolyte abnormalities, in those with CKD.

OBJECTIVES

This review aims to look at the benefits and harms of pharmacological interventions for HF (i.e., antihypertensive agents, inotropes, and agents that may improve the heart performance indirectly) in people with HF and CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies through 12 September 2019 in consultation with an Information Specialist and using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials of any pharmacological intervention for acute or chronic heart failure, among people of any age with chronic kidney disease of at least three months duration.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the records to identify eligible studies and extracted data on the following dichotomous outcomes: death, hospitalisations, worsening heart failure, worsening kidney function, hyperkalaemia, and hypotension. We used random effects meta-analysis to estimate treatment effects, which we expressed as a risk ratio (RR) with 95% confidence intervals (CI). We assessed the risk of bias using the Cochrane tool. We applied the GRADE methodology to rate the certainty of evidence.

MAIN RESULTS

One hundred and twelve studies met our selection criteria: 15 were studies of adults with CKD; 16 studies were conducted in the general population but provided subgroup data for people with CKD; and 81 studies included individuals with CKD, however, data for this subgroup were not provided. The risk of bias in all 112 studies was frequently high or unclear. Of the 31 studies (23,762 participants) with data on CKD patients, follow-up ranged from three months to five years, and study size ranged from 16 to 2916 participants. In total, 26 studies (19,612 participants) reported disaggregated and extractable data on at least one outcome of interest for our review and were included in our meta-analyses. In acute heart failure, the effects of adenosine A1-receptor antagonists, dopamine, nesiritide, or serelaxin on death, hospitalisations, worsening heart failure or kidney function, hyperkalaemia, hypotension or quality of life were uncertain due to sparse data or were not reported. In chronic heart failure, the effects of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB) (4 studies, 5003 participants: RR 0.85, 95% CI 0.70 to 1.02; I2 = 78%; low certainty evidence), aldosterone antagonists (2 studies, 34 participants: RR 0.61 95% CI 0.06 to 6.59; very low certainty evidence), and vasopressin receptor antagonists (RR 1.26, 95% CI 0.55 to 2.89; 2 studies, 1840 participants; low certainty evidence) on death (any cause) were uncertain. Treatment with beta-blockers may reduce the risk of death (any cause) (4 studies, 3136 participants: RR 0.69, 95% CI 0.60 to 0.79; I2 = 0%; moderate certainty evidence). Treatment with ACEi or ARB (2 studies, 1368 participants: RR 0.90, 95% CI 0.43 to 1.90; I2 = 97%; very low certainty evidence) had uncertain effects on hospitalisation for heart failure, as treatment estimates were consistent with either benefit or harm. Treatment with beta-blockers may decrease hospitalisation for heart failure (3 studies, 2287 participants: RR 0.67, 95% CI 0.43 to 1.05; I2 = 87%; low certainty evidence). Aldosterone antagonists may increase the risk of hyperkalaemia compared to placebo or no treatment (3 studies, 826 participants: RR 2.91, 95% CI 2.03 to 4.17; I2 = 0%; low certainty evidence). Renin inhibitors had uncertain risks of hyperkalaemia (2 studies, 142 participants: RR 0.86, 95% CI 0.49 to 1.49; I2 = 0%; very low certainty). We were unable to estimate whether treatment with sinus node inhibitors affects the risk of hyperkalaemia, as there were few studies and meta-analysis was not possible. Hyperkalaemia was not reported for the CKD subgroup in studies investigating other therapies. The effects of ACEi or ARB, or aldosterone antagonists on worsening heart failure or kidney function, hypotension, or quality of life were uncertain due to sparse data or were not reported. Effects of anti-arrhythmic agents, digoxin, phosphodiesterase inhibitors, renin inhibitors, sinus node inhibitors, vasodilators, and vasopressin receptor antagonists were very uncertain due to the paucity of studies.

AUTHORS' CONCLUSIONS

The effects of pharmacological interventions for heart failure in people with CKD are uncertain and there is insufficient evidence to inform clinical practice. Study data for treatment outcomes in patients with heart failure and CKD are sparse despite the potential impact of kidney impairment on the benefits and harms of treatment. Future research aimed at analysing existing data in general population HF studies to explore the effect in subgroups of patients with CKD, considering stage of disease, may yield valuable insights for the management of people with HF and CKD.

Right bundle branch block and cardiovascular morbidity and mortality in healthy patients

The clinical significance of a right bundle branch block (RBBB) in an asymptomatic adult without evidence of cardiovascular disease is controversial. To establish the relationship between the appearance of the RBBB and the increase of cardiovascular morbidity and mortality in healthy patients, we have carried out a literature review of documents available until September 2017 through a systematic search on the Pubmed database, Cochrane library and a manual search of the mentioned literature and related articles. From the 29 articles included in the study sample, eight showed mortality and 16 morbidity outcomes. An increase of risk of death is observed is eight articles and an increase of cardiovascular events is observed in 11 articles. The most recent publications suggest that the appearance of an RBBB in healthy individuals should not be underestimated, thus further studies are needed to analyse the type of follow-up that should be carried out in these patients.

New or presumed new left bundle branch block in patients with suspected ST-elevation myocardial infarction

AIMS

Using a comprehensive large prospective regional ST-elevation myocardial infarction (STEMI) system database, we evaluated the prevalence, clinical and angiographic characteristics, and outcomes in patients with ischemic symptoms and new or presumed new left bundle branch block (LBBB). We then tested a new hierarchical diagnosis and triage algorithm to identify more accurately new LBBB patients with an acute culprit lesion.

METHODS AND RESULTS

From March 2003 to June 2013, 3903 consecutive STEMI patients were treated using the Minneapolis Heart Institute regional STEMI protocol including 131 patients (3.3%) with new LBBB. These patients had fewer culprit arteries (54.2% vs. 86.4%; P<0.001), were older, more commonly women, with a lower ejection fraction, and more frequently presented with cardiac arrest or heart failure than those without new LBBB. At 1 year follow-up, all-cause mortality accounting for baseline differences was higher in patients with new LBBB (hazard ratio 1.73, 95% confidence interval 1.17-2.58; P=0.007). The new algorithm yielded high sensitivity (97%) and negative predictive value (94%) for identification of a culprit lesion. Using the definition of new LBBB with either hemodynamically unstable features or Sgarbossa concordance criteria on electrocardiogram (ECG), 45% of new LBBB patients would have been treated as 'STEMI equivalent'.

CONCLUSION

Patients with acute ischemic symptoms and new LBBB represent a high-risk population with unique clinical challenges. If validated in an independent dataset, the new algorithm may improve the diagnostic accuracy regarding reperfusion therapy for new LBBB patients.

Left ventricular ejection fraction and mortality in patients with ST-elevation myocardial infarction and bundle branch block

BACKGROUND

The aim of our study is to assess the effect of bundle branch block (BBB) on mortality and left ventricular ejection fraction (LVEF) in ST-elevation myocardial infarction (STEMI) patients treated in the current era of percutaneous reperfusion therapy.

PATIENTS AND METHODS

In this retrospective cohort study, a total of 1123 STEMI patients treated in the University Medical Center Groningen from January 2011 until May 2013 were included. The follow-up duration was 2-4 years. Transthoracic echocardiography was performed within 2 weeks after STEMI.

RESULTS

In total, 23 (2.0%) patients presented with left BBB and 49 (4.4%) patients presented with right BBB. Two-year mortality after STEMI was 25.0% (n=18) in patients with BBB and 9.2% (n=97, P<0.001) in patients without BBB. Patients with BBB had more frequently a severely reduced LVEF (<30%) [20.0% (n=6) compared with 4.2% (n=21), P=0.002] and less frequently a normal LVEF [16.7% (n=5) compared with 35.7% (n=179), P=0.046]. After multivariable analysis, BBB did not remain an independent predictor of mortality, but was an independent predictor of reduced LVEF.

CONCLUSION

The presence of a BBB was an independent predictor of a reduced LVEF. However, we found no effect of BBB on 2-year mortality in the current era of percutaneous reperfusion therapy.

Relation of New Permanent Right or Left Bundle Branch Block on Short- and Long-Term Mortality in Acute Myocardial Infarction Bundle Branch Block and Myocardial Infarction

The aim of this study was to investigate the prognosis associated with bundle branch block (BBB) depending on location, time of appearance, and duration in patients with myocardial infarction (MI). From January 1998 to January 2008, we recruited 5,570 patients with acute MI. Thirty-day and 7-year all-cause mortality, according to BBB location, time of appearance, and duration were analyzed by multivariable analyses. BBB was present in 964 patients (17.3%); right BBB (RBBB) 10.6% and left BBB (LBBB) 6.7%. Overall mortality rate at 30 days was 13.2% (n = 738) and 7 years was 6.34 deaths per 100 patient-year. Both RBBB and LBBB were more frequently previous, 42.9% and 58.8%. Compared with non-BBB, all BBB groups showed higher prevalence of co-morbidities, especially rates of diabetes (49.0% vs 34.3%, p <0.001) and more often heart failure during hospitalization (54.5% vs 26.6%, p <0.001). Compared with RBBB, patients with LBBB had a higher prevalence of co-morbidities and a higher mortality, especially the new BBB, 30 days: 52.5% versus 31.6% and 7 years (incident rate): 27.2 versus 13.3 per 100 patient-year. New transient BBB had lower heart failure on admission (42.6% vs 58.3%, p = 0.008) and 30-day mortality (20.3% vs 69.6%, p <0.001) compared with permanent in both locations. New permanent RBBB was independently associated with 30-day (hazard ratio [HR] 2.01, 95% confidence interval [CI] 1.45 to 2.79) and 7-year mortality (HR 3.12, 95% CI 2.38 to 4.09). New-permanent LBBB was independently associated with 30-day (HR 2.15, 95% CI 1.47 to 3.15) and 7-year mortality (HR 2.91, 95% CI 2.08 to 4.08). In conclusion, in patients with acute MI, the appearance of a new BBB was independently associated with a higher 30-day and 7-year all-cause mortality.

Does marital status contribute to the explanation of the hypercholesterolemia paradox in relation to long term mortality in myocardial infarction? Findings from the MONICA/KORA Myocardial Infarction Registry

OBJECTIVE

A recent study found long-term mortality after first acute myocardial infarction (AMI) to be particularly reduced among married individuals with hypercholesterolemia. This study explores, whether statin treatments during the last week prior to AMI offer an explanation to this phenomenon.

METHODS

Data were retrieved 2000-2008 from the population-based KORA myocardial infarction registry, located in Bavaria, Germany. The sample included 3162 individuals, alive 28days after first AMI, who received statins both in hospital and at discharge. Associations with long-term mortality were examined via multivariable Cox regression. Among patients with hypercholesterolemia, individuals with and without prior statin treatment were each tested against the reference group "neither (hypercholesterolemia nor statin)" and tested for interaction with "marital status".

RESULTS

Among patients with and without prior statins, hazard ratio (HR) 0.66, 95% confidence interval (CI) 0.46-0.93 and HR 0.72, 95% CI 0.55-0.94, were observed, respectively. Mortality reductions diminished after introduction of the following interaction terms with marital status: HR 0.49, p 0.042 for patients with and HR 0.77, p 0.370, for patients without prior statins.

CONCLUSIONS

Prior statin treatments appear to be an underlying factor for long-term mortality reduction in married AMI-survivors with hypercholesterolemia. Confirmation of our results in further studies is warranted.

Marital status shows a strong protective effect on long-term mortality among first acute myocardial infarction-survivors with diagnosed hyperlipidemia--findings from the MONICA/KORA myocardial infarction registry

BACKGROUND

Reduction of long term mortality by marital status is well established in general populations. However, effects have been shown to change over time and differ considerably by cause of death. This study examined the effects of marital status on long term mortality after the first acute myocardial infarction.

METHODS

Data were retrieved from the population-based MONICA (Monitoring trends and determinants on cardiovascular diseases)/KORA (Cooperative Health Research in the Region of Augsburg)-myocardial infarction registry which assesses cases from the city of Augsburg and 2 adjacent districts located in southern Bavaria, Germany. A total of 3,766 men and women aged 28 to 74 years who were alive 28 days after their first myocardial infarction were included. Hazard ratios (HR) for the effects of marital status on mortality after one to 10 years of follow-up are presented.

RESULTS

The study population included 2,854 (75.8%) married individuals. During a median follow-up of 5.3 years, with an inter-quartile range of 3.3 to 7.6 years, 533 (14.15%) deaths occurred. Among married and unmarried individuals 388 (13.6%) and 145 (15.9%) deaths occurred, respectively. Overall marital status showed an insignificant protective HR of 0.76 (95% confidence interval (CI) 0.47-1.22). Stratified analyses revealed strong protective effects only among men and women younger than 60 who were diagnosed with hyperlipidemia. HRs ranged from 0.27 (95% CI 0.13-0.59) for a two-year survival to 0.43 (95% CI 0.27-0.68) for a 10-year survival. Substitution of marital status with co-habitation status confirmed the strata-specific effect [HR: 0.52 (95% CI 0.31-0.86)].

CONCLUSIONS

Marital status has a strong protective effect among first myocardial infarction survivors with diagnosed hyperlipidemia, which diminishes with increasing age. Treatments, recommended lifestyle changes or other attributes specific to hyperlipidema may be underlying factors, mediated by the social support of spouses. Underlying causes should be examined in further studies.

Spontaneous recovery of complete atrioventricular block complicating acute anterior wall ST elevation myocardial infarction

BACKGROUND

Complete atrioventricular block complicating acute anterior wall ST elevation myocardial infarction (MI) is classically considered one of the worst prognostic indicators.

METHODS

We present the case of a gentleman who developed complete atrioventricular block during the course of acute anterior wall ST elevation MI, and had spontaneous resolution of the same. Mechanisms of spontaneous resolution of complete atrioventricular block in the setting of acute MI are discussed. Attention is drawn to a subgroup of patients, albeit a minority, who have a better prognosis owing to reversible causes than classically expected and seen.

RESULTS

Clinical features suggested that this patient had reocclusion of the infarct-related artery after thrombolysis on presentation and spontaneous reperfusion.

CONCLUSION

Coronary angiography provides invaluable information for decision making in such clinical scenarios. Complete atrioventricular block due to reversible ischaemia produced by reocclusion of an infarct-related artery should be reversible by percutaneous coronary angioplasty of the infarct-related artery. We suggest that reversible causes be considered before attributing atrioventricular block to irreversible damage, which would require a permanent pacemaker implantation. This would be more significant in most of the developing world, where resources are scarce.

Long-term cardiovascular outcomes in patients with angina pectoris presenting with bundle branch block

Long-term outcomes of unselected patients with angina pectoris and bundle branch block (BBB) on initial electrocardiogram are not well established. The Olmsted County Chest Pain Study is a community-based cohort of 2,271 consecutive patients presenting to 3 Olmsted County emergency departments with angina from 1985 through 1992. Patients were followed for major adverse cardiovascular events (MACEs) including death, myocardial infarction, stroke, and revascularization at 30 days and over a median follow-up period of 7.3 years and for mortality only through a median of 16.6 years. Cox models were used to estimate associations between BBB and cardiovascular outcomes. Mean age of the cohort on presentation was 63 years, and 58% were men. MACEs at 30 days occurred in 11% with right BBB (RBBB), 8.8% with left BBB (LBBB), and 6.4% in patients without BBB (p = 0.17). Over a median follow-up of 7.3 years, patients with BBB were at higher risk for MACEs (RBBB, hazard ratio [HR] 1.85, 95% confidence interval [CI] 1.44 to 2.38, p <0.001; LBBB, HR 2.04, 95% CI 1.62 to 2.56, p <0.001) compared to those without BBB. Over a median of 16.6 years, the 2 BBB groups had lower survival rates than patients without BBB (RBBB, HR 2.19, 95% CI 1.73 to 2.78, p <0.001; LBBB, HR 3.32, 95% CI 2.67 to 4.13, p ≤0.001), but after adjustment for multiple risk factors an increased risk of mortality for LBBB remained significant. In conclusion, appearance of LBBB or RBBB in patients presenting with angina predicts adverse long-term cardiovascular outcomes compared to patients without BBB.

Right bundle-branch block in acute coronary syndrome: diagnostic and therapeutic implications for the emergency physician

Right bundle-branch block (RBBB) in the patient with acute coronary syndrome is a marker of significant potential cardiovascular risk; the RBBB pattern in the patient with acute coronary syndrome identifies a subgroup of patients with quite high short- and long-term morbidity and mortality. Right bundle-branch block is not an uncommon finding on an electrocardiogram in the emergency department patient, noted incidentally and thus without clinical import or, conversely, encountered in the early phase of significant cardiovascular dysfunction. This review will address RBBB in the acute coronary syndrome setting.

20-year trends in clinical characteristics, therapy and short-term prognosis in acute myocardial infarction according to presenting electrocardiogram: the MONICA/KORA AMI Registry (1985-2004)

OBJECTIVES

To examine the extent to which evidence-based beneficial therapy is applied in practice, whether this is changing over time and is associated with improved outcomes.

BACKGROUND

Randomized trials have proved efficacy of several treatments for acute myocardial infarction (AMI) with ST-elevation (STEMI), non-ST-elevation (NSTEMI) and bundle branch block (BBB).

DESIGN AND SETTING

We prospectively examined all 6748 consecutive patients with AMI aged 25-74 years hospitalized in the study region's major clinic stratified into four time-periods: 1985-1989 (n = 1622), 1990-1994 (n = 1588), 1995-1999 (n = 1450) and 2000-2004 (n = 2088).

RESULTS

The increase in numbers of AMI in the last period was mainly, but not exclusively driven by NSTEMI cases. Evidence-based pharmacological therapy increased steeply over time. Invasive procedures increased mainly in the last period with percutaneous coronary intervention and coronary artery bypass graft performed in 30% and 15% in 1998 and 66.0% and 22%, respectively, in 2004. In-hospital complications and 28-day-case fatality decreased significantly from period 1 to period 4 in all patients with AMI. Marked reductions in 28-day-case fatality were mostly seen in BBB patients during the last period (25.3% vs. 10.3%, P < 0.001). Of interest, the odds in 28-day-case fatality reduction was diminished after correction for recanalization therapy (from 0.35, 95% CI: 0.16-0.74 to 0.52, 95% CI: 0.19-1.45).

CONCLUSIONS

Over the past 20 years, there were substantial changes in pharmacological and interventional therapies in AMI accompanied by reductions in in-hospital complications and 28-day-case fatality in all infarction types with marked reductions in 28-day-case fatality in BBB patients. The latter observation may mainly be because of the increased use of interventional therapy.