Prognostic impact of left bundle-branch block in the early stable phase after acute myocardial infarction

First outline and baseline data of a randomized, controlled multicenter trial to evaluate the health economic impact of home telemonitoring in chronic heart failure - CardioBBEAT

Background

Evidence that home telemonitoring for patients with chronic heart failure (CHF) offers clinical benefit over usual care is controversial as is evidence of a health economic advantage.

Methods

Between January 2010 and June 2013, patients with a confirmed diagnosis of CHF were enrolled and randomly assigned to 2 study groups comprising usual care with and without an interactive bi-directional remote monitoring system (Motiva®). The primary endpoint in CardioBBEAT is the Incremental Cost-Effectiveness Ratio (ICER) established by the groups’ difference in total cost and in the combined clinical endpoint “days alive and not in hospital nor inpatient care per potential days in study” within the follow-up of 12 months.

Results

A total of 621 predominantly male patients were enrolled, whereof 302 patients were assigned to the intervention group and 319 to the control group. Ischemic cardiomyopathy was the leading cause of heart failure. Despite randomization, subjects of the control group were more often in NYHA functional class III–IV, and exhibited peripheral edema and renal dysfunction more often. Additionally, the control and intervention groups differed in heart rhythm disorders. No differences existed regarding risk factor profile, comorbidities, echocardiographic parameters, especially left ventricular and diastolic diameter and ejection fraction, as well as functional test results, medication and quality of life. While the observed baseline differences may well be a play of chance, they are of clinical relevance. Therefore, the statistical analysis plan was extended to include adjusted analyses with respect to the baseline imbalances.

Conclusions

CardioBBEAT provides prospective outcome data on both, clinical and health economic impact of home telemonitoring in CHF. The study differs by the use of a high evidence level randomized controlled trial (RCT) design along with actual cost data obtained from health insurance companies. Its results are conducive to informed political and economic decision-making with regard to home telemonitoring solutions as an option for health care. Overall, it contributes to developing advanced health economic evaluation instruments to be deployed within the specific context of the German Health Care System.

Trial registration

ClinicalTrials.gov NCT02293252; date of registration: 10 November 2014

Left bundle branch block and suspected myocardial infarction: does chronicity of the branch block matter?

BACKGROUND

Our aim was to investigate if patients with suspected myocardial infarction (MI) and a new or presumed new left bundle branch block (nLBBB) were treated according to the ESC reperfusion guidelines and to compare them with patients having a previously known LBBB (oLBBB). Furthermore, we investigated the prevalence of ST-segment concordance in this population.

METHODS

Retrospective data was collected from the Swedeheart registry for patients admitted to the cardiac care unit at Örebro University Hospital with LBBB and suspected MI during 2009 and 2010. The patients were divided in two age groups; <80 or ≥80 years and analysed for LBBB chronicity (nLBBB or oLBBB), MI, and reperfusion treatment. We also compared our data with the national Swedeheart database for 2009.

RESULTS

A total of 99 patients fulfilled the inclusion criteria. A diagnosis of MI was significantly more common in the group ≥80 years compared to the group <80 years (53.8 vs. 25%, p=0.007). The rate of MI was similar in the groups with nLBBB and oLBBB (33 and 37% respectively, p=0.912). Of the 36 patients with a final diagnosis of MI, only eight (22%) had nLBBB. Reperfusion treatment, defined as an acute coronary angiography with or without intervention, was significantly more often performed in patients with nLBBB compared to patients with oLBBB (42 vs. 8%, p<0.001). The rate of MI and reperfusion treatment did not differ between our institution and the Swedish national data. ST-concordance was present in only two cases, one of which did not suffer an MI.

CONCLUSIONS

The proportion of patients receiving reperfusion treatment was low, but higher in nLBBB, reflecting a partial adherence to the guidelines. We found no correlation between LBBB chronicity and MI. Furthermore, only a minority of the MIs occurred in patients with nLBBB. ST-concordance was found in only one of 36 MI cases, indicating lack of sensitivity for this test.

Left atrial and left atrial appendage systolic function in patients with post-myocardial distal blocks

INTRODUCTION

The study aimed to evaluate function of the left atrium (LA) and of the left atrial appendage (LAA) after myocardial infarction (MI) complicated by intracardiac conduction disturbances.

MATERIAL AND METHODS

The study comprised 59 patients with persistent post-myocardial distal blocks, who were allocated to one of the three following subgroups: study group I - 20 patients with left bundle branch block (LBBB); study group II - 20 patients with right bundle branch block (RBBB), and study group III -19 pts with left anterior hemiblock (LAHB). The control groups included patients with MI in their history and no BBBs (19 pts - group IV) and clinically healthy people (16 patients - group V). The parameters of LA and LAA systolic function were determined by means of transthoracic (TTE) and transoesophageal echocardiography (TOE).

RESULTS

We showed that patients who experienced myocardial infarction not complicated with conduction disturbances expressed compensatory LA systolic function enhancement. In patients with post-myocardial RBBB and LAHB significant enhancement of LA systolic function was observed as well but it was expressed to a lesser degree. There was also a tendency towards deterioration of LA systolic function in patients with post-myocardial LBBB. LBBB did not affect LAA systolic function negatively.

CONCLUSIONS

Parameters of LAA systolic function showed its enhancement in all patients after myocardial infarction irrespective of whether it was complicated by conduction disturbances.

Clinical practice of defibrillator implantation after myocardial infarction: impact of implant time: results from the PreSCD II registry

Aims

Current guidelines recommend implantable cardioverter-defibrillator (ICD) therapy for primary prevention of sudden cardiac death in patients with the reduced left ventricular function (LVEF ≤30%) not earlier than 40 days after myocardial infarction (MI). The aim of the prospective Prevention of Sudden Cardiac Death II (PreSCD II) registry was to investigate the clinical practice of ICD therapy in post-MI patients and to assess the impact on survival.

Methods and results

10 612 consecutive patients (61 ± 12 years, 76% male) were enrolled 4 weeks or later after MI in 19 cardiac rehabilitation centres in Germany from December 2002 to May 2005. All patients with left ventricular ejection fraction (LVEF) ≤40% (n = 952) together with a randomly selected group of patients with preserved left ventricular function (n = 1106) were followed for 36 months. Cox proportional hazard models were used to correlate ICD implantation and survival with baseline characteristics. Of all patients studied, 75.9% were enrolled within 4–8 weeks, 10.7% more than 1 year after MI. Pre-specified Group 1 with an LVEF ≤30% consisted of 269 patients (2.5%), Group 2 with LVEF 31–40% of 727 patients (6.9%), and Group 3 with LVEF >40% of 1148 randomly selected patients from the cohort of 9616 patients with preserved LV function. After 36 months, only 142 patients (6.9%) had received an ICD; 82 (31.7%) of Group 1, 49 (7%) of Group 2, and 11 (1%) in Group 3. The ICD was implanted in 47% of all patients within 1 year after their index MI. Implantable cardioverter-defibrillator patients were predominantly characterized by low ejection fraction, but also by several other independent risk factors. Patients who received an ICD had an adjusted 44% lower mortality (hazard ratio 0.56, 95% confidence intervals 0.32–1.01; P = 0.053) than comparable patients without ICD therapy. All cause mortality of ICD recipients was significantly lower if the ICD was implanted later than 11 months after acute MI (P < 0.001).

Conclusions

The PreSCD II registry demonstrated that the number of patients who develop a low LVEF (≤30%) after acute MI is small. However, only few patients with guideline-based ICD indication received ICD therapy. All cause mortality was significantly reduced only if the ICD was implanted late (>11 months) after MI.