Abstract Background Remote monitoring (RM) technology embedded within cardiac rhythm devices permits continuous monitoring, which may result in improved patient outcomes. Objectives This study used ...“big data” to assess whether RM is associated with improved survival and whether this is influenced by the type of cardiac device and/or its degree of use. Methods We studied 269,471 consecutive U.S. patients implanted between 2008 and 2011 with pacemakers (PMs), implantable cardioverter-defibrillators (ICDs), or cardiac resynchronization therapy (CRT) with pacing capability (CRT-P)/defibrillation capability (CRT-D) with wireless RM. We analyzed weekly use and all-cause survival for each device type by the percentage of time in RM (%TRM) stratified by age. Socioeconomic influences on %TRM were assessed using 8 census variables from 2012. Results The group had implanted PMs (n = 115,076; 43%), ICDs (n = 85,014; 32%), CRT-D (n = 61,475; 23%), and CRT-P (n = 7,906; 3%). When considered together, 127,706 patients (47%) used RM, of whom 67,920 (53%) had ≥75%TRM (high %TRM) and 59,786 (47%) <75%TRM (low %TRM); 141,765 (53%) never used RM (RM None). RM use was not affected by age or sex, but demonstrated wide geographic and socioeconomic variability. Survival was better in high %TRM versus RM None (hazard ratio HR: 2.10; p < 0.001), in high %TRM versus low %TRM (HR: 1.32; p < 0.001), and also in low %TRM versus RM None (HR: 1.58; p < 0.001). The same relationship was observed when assessed by individual device type. Conclusions RM is associated with improved survival, irrespective of device type (including PMs), but demonstrates a graded relationship with the level of adherence. The results support the increased application of RM to improve patient outcomes.
Background: RV apical pacing (RVP) may be deleterious, possibly by simulating LBBB, i.e., prolonging QRS duration (QRSd) and LV activation (LVAT). However, determinants of electrical delays are ...unknown.
Hypothesis: LV dysfunction (LVEF ≤ 40%, HF) and pre‐existing conduction system abnormalities may modulate RVP's effects, compared to LBBB.
Methods: RVP‐induced QRSd and LVAT were compared in normal LV to HF, with normal QRS (<120 ms), RBBB, or LBBB. LVAT was estimated by interval from QRS onset to basal inferolateral LV depolarization.
Results: During LBBB and RVP, LVAT/QRSd was ≥85%, i.e., LVAT indicated terminal LV depolarization. In normal LV, LVAT during intrinsic conduction (55 ± 18 ms) was delayed by RVP (129 ± 20 ms, n = 58, P < 0.001). RVP's effects were similar to LBBB (P = NS) and unaffected by baseline conduction disease. In HF overall, RVP‐induced delays (QRSd 209 ± 27, LVAT 186 ± 26 ms, n = 102) were greater than RVP in normal LV (P < 0.001). When baseline conduction system disease was present, RVP's effects were exaggerated (RVP wide QRS >120 ms: QRSd 216 ± 27, LVAT 191 ± 20 ms, n = 72 vs RVP normal QRS: QRSd 193 ± 24, LVAT 169 ± 24 ms, n = 31, P < 0.001). In patients with LBBB (n = 41), delays during intrinsic conduction (QRSd 163 ± 29, LVAT 137 ± 33 ms, n = 41) were enhanced by RVP (QRSd 218 ± 28, LVAT 191 ± 22 ms, P < 0.001). RVP's effects were similar in patients with LBBB and RBBB (P = NS).
Conclusion: RVP simulated LBBB in normal LV. In HF, RVP induced greater conduction delays than LBBB, enhanced by accompanying conduction disease. These variations may contribute to RVP's mixed clinical effects.
Remote monitoring of implantable cardioverter-defibrillators may improve clinical outcome. A recent meta-analysis of three randomized controlled trials (TRUST, ECOST, IN-TIME) using a specific remote ...monitoring system with daily transmissions Biotronik Home Monitoring (HM) demonstrated improved survival. We performed a patient-level analysis to verify this result with appropriate time-to-event statistics and to investigate further clinical endpoints.
Individual data of the TRUST, ECOST, and IN-TIME patients were pooled to calculate absolute risks of endpoints at 1-year follow-up for HM vs. conventional follow-up. All-cause mortality analysis involved all three trials (2405 patients). Other endpoints involved two trials, ECOST and IN-TIME (1078 patients), in which an independent blinded endpoint committee adjudicated the underlying causes of hospitalizations and deaths. The absolute risk of death at 1 year was reduced by 1.9% in the HM group (95% CI: 0.1-3.8%; P = 0.037), equivalent to a risk ratio of 0.62. Also the combined endpoint of all-cause mortality or hospitalization for worsening heart failure (WHF) was significantly reduced (by 5.6%; P = 0.007; risk ratio 0.64). The composite endpoint of all-cause mortality or cardiovascular (CV) hospitalization tended to be reduced by a similar degree (4.1%; P = 0.13; risk ratio 0.85) but without statistical significance.
In a pooled analysis of the three trials, HM reduced all-cause mortality and the composite endpoint of all-cause mortality or WHF hospitalization. The similar magnitudes of absolute risk reductions for WHF and CV endpoints suggest that the benefit of HM is driven by the prevention of heart failure exacerbation.
“Nonresponse” to cardiac resynchronization therapy (CRT) is recognized, but definition(s) applied in practice, treatment(s), and their consequences are little known.
The authors sought to assess ...nonresponse in the prospective, international, ADVANCE CRT registry (Advance Cardiac Resynchronization Therapy Registry).
Each subject’s response was assessed at 6 months post-implantation using site-specific definitions and compared with the independently derived clinical composite score (CCS). Treatment(s) and hospitalization(s) were tracked during the following 6 months.
Of 1,524 subjects enrolled in 69 centers (68 ± 12 years of age, 32% female, ischemic disease 39%), 74.3% received CRT-defibrillator devices, using mainly quadripolar LV leads (75%) deployed laterally (78%). Indications for CRT were wider than past trials. Among 1,327 evaluable subjects, site-defined nonresponse was 20.0% (greater age, comorbidities, ischemic cardiomyopathy, non-left bundle branch block, and lower %CRT pacing vs. responders). Site definitions used mainly clinical criteria (echocardiography infrequently), and underestimated nonresponders by 35% compared with CCS (58% sensitivity vs. CCS). Overall, more site-defined nonresponders received treatment (55.9% vs. 38.3% of responders; p < 0.001) using medication changes and heart failure education, but device programming less frequently. Intensification of in-clinic/remote evaluations and involvement of heart failure specialists remained minimal. Remarkably, 44% of site-defined nonresponders received no additional treatment. Frequency and duration of hospitalizations, and death, among site-defined nonresponders was significantly higher than responders.
A high incidence of CRT nonresponders persists despite good patient selection and LV lead position, but site identification methods have modest sensitivity. Following diagnosis, nonresponders are often passively managed, without specialty care, with poor outcome. ADVANCE CRT exposes a vulnerable group of heart failure patients. (Advance Cardiac Resynchronization Therapy Registry ADVANCE CRT; NCT01805154)
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Right ventricular (RV) pacing may worsen left ventricular cardiomyopathy in patients with reduced left ventricular ejection fraction (LVEF) and advanced atrioventricular block.
The objectives of this ...study were to calculate incidence and identify predictors of RV pacing-induced cardiomyopathy (PICM) in complete heart block (CHB) with preserved LVEF and to describe outcomes of subsequent cardiac resynchronization therapy (CRT) upgrade.
An analysis of consecutive patients receiving permanent pacemaker (PPM) from 2000 to 2014 for CHB with LVEF >50% was performed. PICM was defined as CRT upgrade or post-PPM LVEF ≤40%. PICM association was determined via multivariable regression analysis. CRT response was defined by LVEF increase ≥10% or left ventricular end-systolic volume decrease ≥15%.
Of the 823 study patients, 101 (12.3%) developed PICM over the mean follow-up of 4.3 ± 3.9 years, with post-PPM LVEF being 33.7% ± 7.4% in patients with PICM vs 57.6% ± 6.1% in patients without PICM (P < .001). In multivariable analysis, lower pre-PPM LVEF (hazard ratio HR 1.047 per 1% LVEF decrease; 95% confidence interval CI 1.002-1.087; P = .042) and RV pacing % both as a continuous (HR 1.011 per 1% RV pacing; 95% CI 1.002-1.02; P = .021) and as a categorical (<20% or ≥20% RV pacing) (HR 6.76; 95% CI 2.08-22.0; P = .002) variable were independently associated with PICM. Only 29 patients with PICM (28.7%) received CRT upgrade despite an 84% responder rate (LVEF increase 18.5% ± 8.1% and left ventricular end-systolic volume decrease 45.1% ± 15.0% in responders). CRT upgrade was associated with greater post-PPM LVEF decrease, lower post-PPM LVEF, and post-PPM LVEF ≤35% (P = .006, P = .004, and P = .004, respectively).
PICM is not uncommon in patients receiving PPM for CHB with preserved LVEF and is strongly associated with RV pacing burden >20%. CRT response rate is high in PICM, but is perhaps underutilized.
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