Cardiac Resynchronization Therapy Using Quadripolar Versus Non‐Quadripolar Left Ventricular Leads Programmed to Biventricular Pacing With Single‐Site Left Ventricular Pacing:Impact on Survival and Heart Failure Hospitalization

Background: In cardiac resynchronization therapy (CRT), quadripolar (QUAD) left ventricular (LV) leads are less prone to postoperative complications than non‐QUAD leads. Some studies have suggested better clinical outcomes. Methods and Results: Clinical events were assessed in 847 patients after CRT‐pacing or CRT‐defibrillation using either QUAD (n=287) or non‐QUAD (n=560), programmed to single‐site site LV pacing. Over a follow‐up period of 3.2 years (median [interquartile range, 1.90–5.0]), QUAD was associated with a lower total mortality (adjusted hazard ratio [aHR]: 0.32, 95% confidence interval [CI], 0.20–0.52), cardiac mortality (aHR: 0.36, 95% CI, 0.20–0.65), and heart failure (HF) hospitalization (aHR: 0.62, 95% CI, 0.39–0.99), after adjustment for age, sex, New York Heart Association class, HF etiology, device type (CRT‐pacing or CRT‐defibrillation), comorbidities, atrial rhythm, medication, left ventricular ejection fraction, and creatinine. Death from pump failure was lower with QUAD (aHR: 0.33; 95% CI, 0.18–0.62), but no group differences emerged with respect to sudden cardiac death. There were no differences in implant‐related complications. Re‐interventions for LV displacement or phrenic nerve stimulation, which were lower with QUAD, predicted total mortality (aHR: 1.68, 95% CI, 1.11–2.54), cardiac mortality (aHR: 2.61, 95% CI, 1.66–4.11) and HF hospitalization (aHR: 2.09, 95% CI, 1.22–3.58). Conclusions: CRT using QUAD, programmed to biventricular pacing with single‐site LV pacing, is associated with a lower total mortality, cardiac mortality, and HF hospitalization. These trends were observed for both CRT‐defibrillation and CRT‐pacing, after adjustment for HF cause and other confounders. Re‐intervention for LV lead displacement or phrenic nerve stimulation was associated with worse outcomes

Sex‐Specific Differences in Survival and Heart Failure Hospitalization After Cardiac Resynchronization Therapy With or Without Defibrillation

Background Women are underrepresented in cardiac resynchronization therapy (CRT) trials. Some studies suggest that women fare better than men after CRT. We sought to explore clinical outcomes in women and men undergoing CRT-defibrillation or CRT-pacing in real-world clinical practice. Methods and Results A national database (Hospital Episode Statistics for England) was used to quantify clinical outcomes in 43 730 patients (women: 10 890 [24.9%]; men: 32 840 [75.1%]) undergoing CRT over 7.6 years, (median follow-up 2.2 years, interquartile range, 1-4 years). In analysis of the total population, the primary end point of total mortality (adjusted hazard ratio [aHR], 0.73; 95% CI, 0.69-0.76) and the secondary end point of total mortality or heart failure hospitalization (aHR, 0.79, 95% CI 0.75-0.82) were lower in women, independent of known confounders. Total mortality (aHR, 0.73; 95% CI, 0.70-0.76) and total mortality or heart failure hospitalization (aHR, 0.79; 95% CI, 0.75-0.82) were lower for CRT-defibrillation than for CRT-pacing. In analyses of patients with (aHR, 0.89; 95% CI, 0.80-0.98) or without (aHR, 0.70; 95% CI, 0.66-0.73) a myocardial infarction, women had a lower total mortality. In sex-specific analyses, total mortality was lower after CRT-defibrillation in women (aHR, 0.83; P=0.013) and men (aHR, 0.69; P<0.001). Conclusions Compared with men, women lived longer and were less likely to be hospitalized for heart failure after CRT. In both sexes, CRT-defibrillation was superior to CRT-pacing with respect to survival and heart failure hospitalization. The longest survival after CRT was observed in women without a history of myocardial infarction

Changes in QRS Area and QRS Duration After Cardiac Resynchronization Therapy Predict Cardiac Mortality, Heart Failure Hospitalizations, and Ventricular Arrhythmias

Background Predicting clinical outcomes after cardiac resynchronization therapy (CRT) and its optimization remain a challenge. We sought to determine whether pre- and postimplantation QRS area (QRS area) predict clinical outcomes after CRT. Methods and Results In this retrospective study, QRS area, derived from pre- and postimplantation vectorcardiography, were assessed in relation to the primary end point of cardiac mortality after CRT with or without defibrillation. Other end points included total mortality, total mortality or heart failure (HF) hospitalization, total mortality or major adverse cardiac events, and the arrhythmic end point of sudden cardiac death or ventricular arrhythmias with or without a shock. In patients (n=380, age 72.0±12.4 years, 68.7% male) undergoing CRT over 7.7 years (median follow-up: 3.8 years [interquartile range 2.3-5.3]), preimplantation QRS area ≥102 μVs predicted cardiac mortality (HR: 0.36; P<0.001), independent of QRS duration (QRSd) and morphology ( P<0.001). A QRS area reduction ≥45 μVs after CRT predicted cardiac mortality (HR: 0.19), total mortality (HR: 0.50), total mortality or heart failure hospitalization (HR: 0.44), total mortality or major adverse cardiac events (HR: 0.43) (all P<0.001) and the arrhythmic end point (HR: 0.26; P<0.001). A concomitant reduction in QRS area and QRSd was associated with the lowest risk of cardiac mortality and the arrhythmic end point (both HR: 0.12, P<0.001). Conclusions Pre-implantation QRS area, derived from vectorcardiography, was superior to QRSd and QRS morphology in predicting cardiac mortality after CRT. A postimplant reduction in both QRS area and QRSd was associated with the best outcomes, including the arrhythmic end point

Cardiac operations and interventions during the COVID-19 pandemic: a nationwide perspective

AIMS : The COVID-19 pandemic has led to a decline in hospitalizations for non-COVID-19-related conditions. We explored the impact of the COVID-19 pandemic on cardiac operations and interventions undertaken in England. METHODS AND RESULTS : An administrative database covering hospital activity for England, the Health Episodes Statistics, was used to assess a total of 286 697 hospitalizations for cardiac operations and interventions, as well as 227 257 hospitalizations for myocardial infarction (MI) and 453 799 for heart failure (HF) from 7 January 2019 to 26 July 2020. Over the 3 months of 'lockdown', total numbers and mean reductions in weekly rates [n (-%)], compared with the same time period in 2019, were: coronary artery bypass grafting [-2507 (-64%)]; percutaneous coronary intervention [-5245 (-28%)]; surgical [-1324 (-41%)] and transcatheter [-284 (-21%)] aortic valve replacement; mitral valve replacement; implantation of pacemakers [-6450 (-44%)], cardiac resynchronization therapy with [-356 (-42%)] or without [-491 (-46%)] defibrillation devices, and implantable cardioverter-defibrillators [-501 (-45%)]; atrial fibrillation ablation [-1902 (-83%)], and other ablations [-1712 (-64%)] (all P < 0.001). Over this period, there were 21 038 fewer procedures than in the reference period in 2019 (P < 0.001). These changes paralleled reductions in hospitalizations for MI [-10 794 (-27%)] and HF [-63 058 (-28%)] (both P < 0.001). CONCLUSIONS : The COVID-19 pandemic has led to substantial reductions in the number of cardiac operations and interventions undertaken. An alternative strategy for healthcare delivery to patients with cardiac conditions during the COVID-19 pandemic is urgently needed

Long-term outcomes of cardiac resynchronization therapy in adult congenital heart disease

Background and Aims: Randomized, controlled trials of cardiac resynchronization therapy (CRT) excluded patients with adult congenital heart disease (ACHD). We sought to explore long-term clinical outcomes. Methods and Results: In this single-center, observational study, events were collected from hospital records on patients with structural ACHD (sACHD) and adults with ischemic (ICM) or nonischemic (NICM) cardiomyopathy undergoing CRT. Patients with sACHD (n = 23, age: 41.6 ± 13.5 years [mean ± standard deviation]) and adults with ICM (n = 533) or NICM (n = 458) were followed-up for 4.1 years (median; interquartile range: 2.2-6.1). Total mortality was 5/23 (21.7%; 4.4 per 100 person-years) in sACHD, 221/533 (41.5%; 11.8 per 100 person-years) in ICM, and 154/458 (33.6%; 9.7 per 100 person-years) in NICM. In univariate analyses, total mortality in sACHD was lower than in ICM (hazard ratio [HR]: 0.38; 95% confidence interval [CI] 0.15-0.91), but similar to NICM (HR: 0.48, 95% CI 0.20-1.16). Cardiac mortality in sACHD was similar to ICM (HR: 0.78, 95% CI 0.32-1.92) and NICM (HR: 1.12, 95% CI 0.45-2.78). Heart failure (HF) hospitalization rates were similar to ICM (HR: 0.44, 95% CI 0.11-1.77) and NICM (HR: 0.75, 95% CI 0.18-3.08). In multivariate analyses, no differences emerged in total mortality, cardiac mortality, or HF hospitalization between sACHD and NICM or ICM, after adjustment for age, sex, New York Heart Association class, diabetes, atrial rhythm, QRS duration, QRS morphology, systemic ventricular ejection fraction, and medical therapy. Conclusion: Total mortality, cardiac mortality, and HF hospitalization after CRT in patients with sACHD was similar to adults with ICM or NICM

Survival after cardiac resynchronization therapy: results from 50 084 implantations

Aims Randomized controlled trials have shown that cardiac resynchronization therapy (CRT) prolongs survival in patients with heart failure. No studies have explored survival after CRT in relation to individuals in the general population (relative survival, RS). We sought to determine observed and RS after CRT in a nationwide cohort undergoing CRT. Methods and results A national administrative database was used to quantify observed mortality for patients undergoing CRT. Relative survival (RS) was quantified using life tables. In 50 084 patients [age 72.1 ± 11.6 years (mean ± standard deviation)] undergoing CRT with (CRT-D) (n = 25 273) or without (CRT-P) defibrillation (n = 24 811) over 8.8 years (median follow-up 2.7 years, interquartile range 1.3–4.8), expected survival decreased with age. Device type, male sex, ischaemic heart disease, diabetes, and chronic kidney disease predicted excess mortality. In multivariate analyses, excess mortality (analogue of RS) was lower after CRT-D than after CRT-P in all patients [adjusted hazard ratio (aHR) 0.80, 95% confidence interval (CI) 0.76–0.84] as well as in subgroups with (aHR 0.79, 95% CI 0.74–0.84) or without (aHR 0.82, 95% CI 0.74–0.91) ischaemic heart disease. A Charlson Comorbidity Index (CCI) ≥3 portended a higher excess mortality (aHR 3.04, 95% CI 2.76–3.34). Relative survival was higher in 2015–2017 than in 2009–2011 (aHR 0.64, 95% CI 0.59–0.69). Conclusion Reference RS data after CRT is presented. Sex, ischaemic heart disease, diabetes, chronic kidney disease, and CCI were major determinants of RS after CRT. CRT-D was associated with a higher RS than CRT-P in patients with or without ischaemic heart disease. Relative survival after CRT improved from 2009 to 2017

Outcomes of cardiac resynchronization therapy with or without defibrillation in patients with nonischemic cardiomyopathy

Background Recent studies have cast doubt on the benefit of cardiac resynchronization therapy (CRT) with defibrillation (CRT-D) versus pacing (CRT-P) for patients with nonischemic cardiomyopathy (NICM). Left ventricular myocardial scar portends poor clinical outcomes. Objectives The aim of this study was to determine whether CRT-D is superior to CRT-P in patients with NICM either with (+) or without (−) left ventricular midwall fibrosis (MWF), detected by cardiac magnetic resonance. Methods Clinical events were quantified in patients with NICM who were +MWF (n = 68) or −MWF (n = 184) who underwent cardiac magnetic resonance prior to CRT device implantation. Results In the total study population, +MWF emerged as an independent predictor of total mortality (adjusted hazard ratio [aHR]: 2.31; 95% confidence interval [CI]: 1.45 to 3.68), total mortality or heart failure hospitalization (aHR: 2.02; 95% CI: 1.32 to 3.09), total mortality or hospitalization for major adverse cardiac events (aHR: 2.02; 95% CI: 1.32 to 3.07), death from pump failure (aHR: 1.95; 95% CI: 1.11 to 3.41), and sudden cardiac death (aHR: 3.75; 95% CI: 1.26 to 11.2) over a maximum follow-up period of 14 years (median 3.8 years [interquartile range: 2.0 to 6.1 years] for +MWF and 4.6 years [interquartile range: 2.4 to 8.3 years] for −MWF). In separate analyses of +MWF and −MWF, total mortality (aHR: 0.23; 95% CI: 0.07 to 0.75), total mortality or heart failure hospitalization (aHR: 0.32; 95% CI: 0.12 to 0.82), and total mortality or hospitalization for major adverse cardiac events (aHR: 0.30; 95% CI: 0.12 to 0.78) were lower after CRT-D than after CRT-P in +MWF but not in −MWF. Conclusions In patients with NICM, CRT-D was superior to CRT-P in +MWF but not −MWF. These findings have implications for the choice of device therapy in patients with NICM

Laser Doppler flow for the hemodynamic differentiation of tachycardia

Background: Implantable cardioverter defibrillators (ICDs) offer effective therapy for the prevention of sudden cardiac death (SCD) due to ventricular arrhythmias. However, inappropriate shocks have detrimental effects on survival and quality of life. The addition of hemodynamic monitoring may be useful in discriminating clinically important ventricular arrhythmias. Objective: In this study, we assess the ability of laser Doppler flowmetry to assess the hemodynamic effect of paced atrial and ventricular arrhythmias using mean arterial blood pressure as the reference. Methods: In this acute human study in patients undergoing an elective electrophysiological study, laser Doppler flowmetry, arterial blood pressure, and surface ECG were acquired during high‐rate atrial and ventricular pacing to simulate supraventricular and ventricular tachycardias. Results: Arterial blood pressure and laser Doppler flow signals correlated well during atrial and ventricular pacing (rho = 0.694, p < .001). The hemodynamic impairment detected by both methods was greater during ventricular pacing than atrial pacing (–1.0% vs. 19.0%, p < .001). Laser Doppler flowmetry performed better than rate alone to identify hemodynamic impairments. Conclusion: In this acute study, laser Doppler flowmetry tissue perfusion served as a good surrogate measure for arterial pressure, which could be incorporated into future ICDs

Improved prognosis after cardiac resynchronization therapy over a decade

Aims The past decade has seen an increased delivery of cardiac resynchronization therapy (CRT) for patients with heart failure (HF). We explored whether clinical outcomes after CRT have changed from the perspective of an entire public healthcare system. Methods and results A national database covering the population of England (56.3 million in 2019) was used to explore clinical outcomes after CRT from 2010 to 2019. A total of 64 698 consecutive patients (age 71.4 ± 11.7 years; 74.8% male) underwent CRT-defibrillation [n = 32 313 (49.7%)] or CRT-pacing [n = 32 655 (50.3%)] implantation. From 2010–2011 to 2018–2019, there was a 76% increase in CRT implantations. During the same period, the proportion of patients with hypertension (59.6–73.4%), diabetes (26.5–30.8%), and chronic kidney disease (8.62–22.5%) increased, as did the Charlson comorbidity index (CCI ≥ 3 from 20.0% to 25.1%) (all P < 0.001). Total mortality decreased at 30 days (1.43–1.09%) and 1 year (9.51–8.13%) after implantation (both P < 0.001). At 2 years, total mortality [hazard ratio (HR): 0.72; 95% confidence interval (CI) 0.69–0.76] and total mortality or HF hospitalization (HR: 0.59; 95% CI 0.57–0.62) decreased from 2010–2011 to 2018–2019, after correction for age, race, sex, device type (CRT-defibrillation or pacing), comorbidities (hypertension, diabetes, chronic kidney disease, and myocardial infarction), or the CCI (HR: 0.81; 95% CI 0.77–0.85). Conclusions From the perspective of an entire public health system, survival has improved and HF hospitalizations have decreased after CRT implantation over the past decade. This prognostic improvement has occurred despite an increasing comorbidity burden

Timing of cardiac resynchronization therapy implantation

AbstractAimsThe optimum timing of cardiac resynchronization therapy (CRT) implantation is unknown. We explored long-term outcomes after CRT in relation to the time interval from a first heart failure hospitalization (HFH) to device implantation.Methods and resultsA database covering the population of England (56.3 million in 2019) was used to quantify clinical outcomes after CRT implantation in relation to first HFHs. From 2010 to 2019, 64 968 patients [age: 71.4 ± 11.7 years; 48 606 (74.8%) male] underwent CRT implantation, 57% in the absence of a previous HFH, 12.9% during the first HFH, and 30.1% after ≥1 HFH. Over 4.54 (2.80–6.71) years [median (interquartile range); 272 989 person-years], the time in years from the first HFH to CRT implantation was associated with a higher risk of total mortality [hazard ratio (HR); 95% confidence intervals (95% CI)] (1.15; 95% CI 1.14–1.16, HFH (HR: 1.26; 95% CI 1.24–1.28), and the combined endpoint of total mortality or HFH (HR: 1.19; 95% CI 1.27–1.20) than CRT in patients with no previous HFHs, after co-variate adjustment. Total mortality (HR: 1.67), HFH (HR: 2.63), and total mortality or HFH (HR: 1.92) (all P &lt; 0.001) were highest in patients undergoing CRT ≥2 years after the first HFH.ConclusionIn this study of a healthcare system covering an entire nation, delays from a first HFH to CRT implantation were associated with progressively worse long-term clinical outcomes. The best clinical outcomes were observed in patients with no previous HFH and in those undergoing CRT implantation during the first HFH.Condensed abstractThe optimum timing of CRT implantation is unknown. In this study of 64 968 consecutive patients, delays from a first heart failure hospitalization (HFH) to CRT implantation were associated with progressively worse long-term clinical outcomes. Each year from a first HFH to CRT implantation was associated with a 21% higher risk of total mortality and a 34% higher risk of HFH. The best outcomes after CRT were observed in patients with no previous HFHs and in those undergoing implantation during their first HFH