Background

Left bundle branch block (LBBB) has been proposed as a risk factor for cardiovascular morbidity and mortality. We sought to characterize the strength of these associations in a population without preexisting clinical heart disease.

Methods

The association between LBBB and new-onset congestive heart failure (CHF) or death from cardiovascular diseases was examined in 1,688 participants enrolled in the SPPARCS study who were free of known CHF or previous myocardial infarction. SPPARCS is a community-based cohort study in residents of Sonoma, California that are > 55 years. Medical history and 12-lead ECGs were obtained every 2 years for up to 6 years of follow-up. LBBB at enrollment or year 2 was considered "baseline" and assessed as a predictor of CHF and cardiovascular death ascertained at years 4 and 6.

Results

The prevalence of LBBB at baseline was 2.5% (n = 42). During 6 years of follow-up, 70 (4.8%) people developed new CHF. Incidence of CHF was higher in patients with LBBB than in participants without LBBB. This association persisted after controlling for potential confounders (odds ratio (OR): 2.85; 95% confidence interval (CI): 1.01 - 8.02; P = 0.047). A higher mortality from cardiovascular diseases was also found in participants with LBBB after adjusting for potential confounders (OR: 2.35, 95%CI: 1.02 - 5.41; P = 0.044).

Conclusions

LBBB in the absence of a clinically detectable heart disease is associated with new-onset CHF and death from cardiovascular diseases. Further study is warranted to determine if additional diagnostic testing or earlier treatment in patients with asymptomatic LBBB can decrease cardiovascular morbidity or mortality.

Background

Rotating and laser sheaths are both routinely used in transvenous lead extraction (TLE) which can lead to catastrophic complications including death. The efficacy and risk of each approach are uncertain. To perform a meta-analysis to compare success and mortality rates associated with rotating and laser sheaths.

Methods

We searched electronic academic databases for case series of consecutive patients and randomized controlled trials published 1998-2017 describing the use of rotating and laser sheaths for TLE. Among 48 studies identified, rotating sheaths included 1,094 patients with 1,955 leads in 14 studies, and laser sheaths included 7,775 patients with 12,339 leads in 34 studies. Patients receiving rotating sheaths were older (63 versus 60 years old) and were more often male (74% versus 72%); CRT-P/Ds were more commonly extracted using rotating sheaths (12% versus 7%), whereas ICDs were less common (37% versus 42%), p > 0.05 for all. Infection as an indication for lead extraction was higher in the rotating sheath group (59.8% versus 52.9%, p = 0.002). The mean time from initial lead implantation was 7.2 years for rotating sheaths and 6.3 years for laser sheaths (p > 0.05).

Results

Success rates for complete removal of transvenous leads were 95.1% in rotating sheaths and 93.4% in laser sheaths (p < 0.05). There was one death among 1,094 patients (0.09%) in rotating sheaths and 66 deaths among 7,775 patients (0.85%) in laser sheaths, translating to a 9.3-fold higher risk of death with laser sheaths (95% CI 1.3 to 66.9, p = 0.01).

Conclusions

Laser sheaths were associated with lower complete lead removal rate and a 9.3-fold higher risk of death.

Background: Prolonged heart rate-corrected QT (QTc) interval has been associated with incident cardiovascular diseases (CVD) in general Western populations. However, this association is unclear in Asian population. We aim to estimate the association between QTc interval and incident CVD in a general Chinese population. Methods: We analyzed 8,867 participants age ≥35 years and free of CVD at baseline in the Northeast China Rural Cardiovascular Health Study. A resting 12-lead electrocardiogram was performed on all participants, and QTc interval computed using the Framingham formula. Cox proportional hazards models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for associations between QTc interval and incident stroke, coronary heart disease, and combined CVD events. Results: Over a median follow-up of 4.66 years, a total of 439 CVD events occurred (298 stroke cases and 152 CHD cases). After full adjustment, prolonged QTc defined by a sex-specific cutoff was associated with increased risk of developing stroke (HR: 1.82, 95% CI 1.20-2.75, P = 0.004) and combined CVD (HR: 1.52, 95% CI 1.05-2.19, P = 0.026). Spline analyses demonstrated no clear thresholds; when modeled as a linear relationship, each 10 ms increase of QTc interval was associated with an HR of 1.12 (95% CI 1.06-1.19, P < 0.001) for stroke and an HR of 1.10 (95% CI 1.05-1.15, P < 0.001) for combined CVD. Baseline QTc interval was not associated with incident CHD with either modeling strategy. Conclusions: Baseline QTc interval is associated with incident stroke and CVD in adults without prior CVD from a general Chinese population.

Background

Atrial refractoriness may be an important determinant of atrial fibrillation (AF) risk, but its measurement is not clinically accessible. Because the QT interval predicts incident AF and the atrium and ventricle share repolarizing ion currents, we investigated the association between an individual's QT interval and atrial effective refractory period (AERP).

Methods

In paroxysmal AF patients presenting for catheter ablation, the QT interval was measured from the surface 12-lead electrocardiogram. The AERP was defined as the longest S1-S2 coupling interval without atrial capture using a 600-ms drive cycle length.

Results

In 28 patients, there was a positive correlation between QTc and mean AERP. After multivariate adjustment, a 1-ms increase in QTc predicted a 0.70-ms increase in AERP.

Conclusions

The QTc interval reflects the AERP, suggesting that the QTc interval may be used as a marker of atrial refractoriness relevant to assessing AF risk and mechanism-specific therapeutic strategies.

Background

Vest Prevention of Early Sudden Death Trial did not demonstrate a significant reduction in arrhythmic death with the wearable cardioverter-defibrillator (WCD), but compliance with the device may have substantially affected the results. ThePletcher influence of WCD compliance on outcomes has not yet been fully evaluated.

Methods

Using linear and pooled logistic models, we performed as-treated analyses omitting person-time in the hospital and adjusted for correlates of WCD compliance. To assess the impact of early stopping of WCD, we performed a per-protocol Kaplan-Meier analysis, censoring after the last day the WCD was worn. Interactions of potential effect modifiers with treatment assignment and WCD compliance on outcomes were investigated. Finally, we used linear models to identify predictors of WCD compliance.

Results

A per-protocol analysis demonstrated a significant reduction in total (P < .001) and arrhythmic (P = .001) mortality. Better WCD compliance was independently predicted by cardiac arrest during index myocardial infarction (MI), higher Cr, diabetes, prior heart failure, EF ≤ 25%, Polish enrolling center and number of WCD alarms, while worse compliance was predicted by being divorced, Asian race, higher body mass index, prior percutaneous coronary intervention, or any WCD shock. Neither excluding time in hospital from the as-treated analysis nor adjustment for factors affecting WCD compliance materially changed the results. No variable demonstrated a significant interaction in either the intention-to-treat or as-treated analysis.

Conclusion

Robust sensitivity analyses of as-treated and per-protocol analyses suggest that the WCD is protective in compliant patients with ejection fraction less than or equal to 35% during the first 3 months post-MI.

Background

Transseptal puncture is a critical step in achieving left atrial (LA) access for a variety of cardiac procedures. Although the mechanical Brockenbrough needle has historically been used for this procedure, a needle employing radiofrequency (RF) energy has more recently been approved for clinical use. We sought to investigate the comparative effectiveness of an RF versus conventional needle for transseptal LA access.

Methods and results

In this prospective, single-blinded, controlled trial, 72 patients were randomized in a 1:1 fashion to an RF versus conventional (BRK-1) transseptal needle. In an intention-to-treat analysis, the primary outcome was time required for transseptal LA access. Secondary outcomes included failure of the assigned needle, visible plastic dilator shavings from needle introduction, and any procedural complication. The median transseptal puncture time was 68% shorter using the RF needle compared with the conventional needle (2.3 minutes [interquartile range {IQR}, 1.7 to 3.8 minutes] versus 7.3 minutes [IQR, 2.7 to 14.1 minutes], P = 0.005). Failure to achieve transseptal LA access with the assigned needle was less common using the RF versus conventional needle (0/36 [0%] versus 10/36 [27.8%], P < 0.001). Plastic shavings were grossly visible after needle advancement through the dilator and sheath in 0 (0%) RF needle cases and 12 (33.3%) conventional needle cases (P < 0.001). There were no differences in procedural complications (1/36 [2.8%] versus 1/36 [2.8%]).

Conclusions

Use of an RF needle resulted in shorter time to transseptal LA access, less failure in achieving transseptal LA access, and fewer visible plastic shavings.

Background

Persistent severe left ventricular (LV) systolic dysfunction after myocardial infarction (MI) is associated with increased mortality and is a class I indication for implantation of a cardioverter-defibrillator.

Objectives

This study developed models and assessed independent predictors of LV recovery to >35% and ≥50% after 90-day follow-up in patients presenting with acute MI and severe LV dysfunction.

Methods

Our multicenter prospective observational study enrolled participants with ejection fraction (EF) of ≤35% at the time of MI (n = 231). Predictors for EF recovery to >35% and ≥50% were identified after multivariate modeling and validated in a separate cohort (n = 236).

Results

In the PREDICTS (PREDiction of ICd Treatment Study) study, 43% of patients had persistent EF ≤35%, 31% had an EF of 36% to 49%, and 26% had an EF ≥50%. The model that best predicted recovery of EF to >35% included EF at presentation, length of stay, prior MI, lateral wall motion abnormality at presentation, and peak troponin. The model that best predicted recovery of EF to ≥50% included EF at presentation, peak troponin, prior MI, and presentation with ventricular fibrillation or cardiac arrest. After predictors were transformed into point scores, the lowest point scores predicted a 9% and 4% probability of EF recovery to >35% and ≥50%, respectively, whereas profiles with the highest point scores predicted an 87% and 49% probability of EF recovery to >35% and ≥50%, respectively.

Conclusions

In patients with severe systolic dysfunction following acute MI with an EF ≤35%, 57% had EF recovery to >35%. A model using clinical variables present at the time of MI can help predict EF recovery.

Background

Despite the high rate of sudden death after myocardial infarction among patients with a low ejection fraction, implantable cardioverter-defibrillators are contraindicated until 40 to 90 days after myocardial infarction. Whether a wearable cardioverter-defibrillator would reduce the incidence of sudden death during this high-risk period is unclear.

Methods

We randomly assigned (in a 2:1 ratio) patients with acute myocardial infarction and an ejection fraction of 35% or less to receive a wearable cardioverter-defibrillator plus guideline-directed therapy (the device group) or to receive only guideline-directed therapy (the control group). The primary outcome was the composite of sudden death or death from ventricular tachyarrhythmia at 90 days (arrhythmic death). Secondary outcomes included death from any cause and nonarrhythmic death.

Results

Of 2302 participants, 1524 were randomly assigned to the device group and 778 to the control group. Participants in the device group wore the device for a median of 18.0 hours per day (interquartile range, 3.8 to 22.7). Arrhythmic death occurred in 1.6% of the participants in the device group and in 2.4% of those in the control group (relative risk, 0.67; 95% confidence interval [CI], 0.37 to 1.21; P=0.18). Death from any cause occurred in 3.1% of the participants in the device group and in 4.9% of those in the control group (relative risk, 0.64; 95% CI, 0.43 to 0.98; uncorrected P=0.04), and nonarrhythmic death in 1.4% and 2.2%, respectively (relative risk, 0.63; 95% CI, 0.33 to 1.19; uncorrected P=0.15). Of the 48 participants in the device group who died, 12 were wearing the device at the time of death. A total of 20 participants in the device group (1.3%) received an appropriate shock, and 9 (0.6%) received an inappropriate shock.

Conclusions

Among patients with a recent myocardial infarction and an ejection fraction of 35% or less, the wearable cardioverter-defibrillator did not lead to a significantly lower rate of the primary outcome of arrhythmic death than control. (Funded by the National Institutes of Health and Zoll Medical; VEST ClinicalTrials.gov number, NCT01446965 .).

Objectives

This study sought to identify acute changes in human atrial electrophysiology during alcohol exposure.

Background

The mechanism by which a discrete episode of atrial fibrillation (AF) occurs remains unknown. Alcohol appears to increase the risk for AF, providing an opportunity to study electrophysiologic effects that may render the heart prone to arrhythmia.

Methods

In this randomized, double-blinded, placebo-controlled trial, intravenous alcohol titrated to 0.08% blood alcohol concentration was compared with a volume and osmolarity-matched, masked, placebo in patients undergoing AF ablation procedures. Right, left, and pulmonary vein atrial effective refractory periods (AERPs) and conduction times were measured pre- and post-infusion. Isoproterenol infusions and burst atrial pacing were used to assess AF inducibility.

Results

Of 100 participants (50 in each group), placebo recipients were more likely to be diabetic (22% vs. 4%; p = 0.007) and to have undergone a prior AF ablation (36% vs. 22%; p = 0.005). Pulmonary vein AERPs decreased an average of 12 ms (95% confidence interval: 1 to 22 ms; p = 0.026) in the alcohol group, with no change in the placebo group (p = 0.98). Whereas no statistically significant differences in continuously assessed AERPs were observed, the proportion of AERP sites tested that decreased with alcohol (median: 0.5; interquartile range: 0.6 to 0.6) was larger than with placebo (median: 0.4; interquartile range: 0.2 to 0.6; p = 0.0043). No statistically significant differences in conduction times or in the proportion with inducible AF were observed.

Conclusions

Acute exposure to alcohol reduces AERP, particularly in the pulmonary veins. These data demonstrate a direct mechanistic link between alcohol, a common lifestyle exposure, and immediate proarrhythmic effects in human atria. (How Alcohol Induces Atrial Tachyarrhythmias Study [HOLIDAY]; NCT01996943).

Background Long-term corticosteroid therapy is the standard of care for treatment of cardiac sarcoidosis (CS). The efficacy of long-term corticosteroid-sparing immunosuppression in CS is unknown. The goal of this study was to assess the efficacy of methotrexate with or without adalimumab for long-term disease suppression in CS, and to assess recurrence and adverse event rates after immunosuppression discontinuation. Methods and Results Retrospective chart review identified treatment-naive CS patients at a single academic medical center who received corticosteroid-sparing maintenance therapy. Demographics, cardiac uptake of 18-fluorodeoxyglucose, and adverse cardiac events were compared before and during treatment and between those with persistent or interrupted immunosuppression. Twenty-eight CS patients were followed for a mean 4.1 (SD 1.5) years. Twenty-five patients received 4 to 8 weeks of high-dose prednisone (>30 mg/day), followed by taper and maintenance therapy with methotrexate±low-dose prednisone (low-dose prednisone, <10 mg/day). Adalimumab was added in 19 patients with persistently active CS or in those with intolerance to methotrexate. Methotrexate±low-dose prednisone resulted in initial reduction (88%) or elimination (60%) of 18-fluorodeoxyglucose uptake, and patients receiving adalimumab-containing regimens experienced improved (84%) or resolved (63%) 18-fluorodeoxyglucose uptake. Radiologic relapse occurred in 8 of 9 patients after immunosuppression cessation, 4 patients on methotrexate-containing regimens, and in no patients on adalimumab-containing regimens. Conclusions Corticosteroid-sparing regimens containing methotrexate with or without adalimumab is an effective maintenance therapy in patients after an initial response is confirmed. Disease recurrence in patients on and off immunosuppression support need for ongoing radiologic surveillance regardless of immunosuppression regimen.