Israel Medical Association Journal

Background: Existing cardiac disease contributes to poor outcome in patients with coronavirus disease 2019 (COVID-19). Little information exists regarding COVID-19 infection in patients with a cardiac implantable electronic device (CIED).

Objectives: To assess the association between CIEDs and severity of COVID-19 infection.

Methods: We performed a retrospective analysis including 13,000 patients > 18 years old with COVID-19 infection between January and December 2020. Patients with COVID-19 who had a permanent pacemaker or defibrillator were matched 1:4 based on age and sex followed by univariate and multivariate analyses. Baseline characteristics and clinical outcomes were assessed.

Results: Forty patients with CIED and 160 patients without CIED were included in the current analysis. Mean age was 72.6 ± 13 years, and approximately 50% were females. Majority of the patients in the study arm had a pacemaker (63%), whereas only 15 patients (37%) had a defibrillator. Patients with COVID-19 and CIED presented more often with atrial fibrillation, coronary artery disease, heart failure, hypertension, diabetes, and chronic kidney disease. They were more likely to be hospitalized in the intensive care unit (ICU) and required more ventilatory support (35% vs. 18.3%). Thirty-day mortality (22.5% vs. 13.8%) and 1-year mortality (25% vs. 15%) were higher among patients with COVID-19 and CIED.

Conclusions: Patients with COVID-19 and CIED had a significantly higher prevalence of co-morbidities that were associated with increased mortality. Although,CIED by itself was not found as an independent risk factor for morbidity and mortality, it may serve as a warning for severe illness with COVID-19.

Background: Gender-related differences (GRD) exist in the outcome of patients with cardiac resynchronization therapy (CRT).

Objectives: To assess GRD in patients who underwent CRT.

Methods: A retrospective cohort of 178 patients who were implanted with a CRT in a tertiary center 2005–2009 was analyzed. Primary outcome was 1 year mortality. Secondary endpoints were readmission and complication rates.

Results: No statistically significant difference was found in 1 year mortality rates (14.6% males vs. 11.8% females, P = 0.7) or in readmission rate (50.7% vs. 41.2%, P = 0.3). The complication rate was only numerically higher in women (14.7% vs. 5.6%, P = 0.09). Men more often had CRT-defibrillator (CRT-D) implants (63.2% vs. 35.3%, P = 0.003) and had a higher rate of ischemic cardiomyopathy (79.2% vs. 38.2%, P < 0.001). There was a trend to higher incidence of ventricular fibrillation/ventricular tachycardia in men before CRT implantation (29.9% vs. 14.7%, P = 0.07%). A higher proportion of men upgraded from implantable cardioverter defibrillator (ICD) to CRT-D, 20.8% vs. 8.8%, P = 0.047. On multivariate model, chronic renal failure was an independent predictor of 1 year mortality (hazard ratio [HR] 3.6; 95% confidence interval [95%CI] 1.4–9.5), CRT-D had a protective effect compared to CRT-pacemaker (HR 0.3, 95%CI 0.12–0.81).

Conclusions: No GRD was found in 1 year mortality or readmission rates in patients treated with CRT. There was a trend toward a higher complication rate in females. Men were implanted more often with CRT-D and more frequently underwent upgrading of ICD to CRT-D.

Background: Cardiac resynchronization therapy (CRT) is a non-pharmacological option for patients with heart failure and interventricular dyssynchrony. Elevated red cell distribution width (RDW) reflects higher size and heterogeneity of erythrocytes and is associated with poor outcome in patients with chronic heart failure. 

Objectives: To examine the association between RDW levels and outcomes after CRT implantation.

Methods: We conducted a cohort analysis of 156 patients (126 men, median age 69.0 years) who underwent CRT implantation in our institution during 2004–2008. RDW was measured at three time points before and after implantation. Primary outcome was defined as all-cause mortality, and secondary outcome as hospital re-admissions. We investigated the association between RDW levels and primary outcome during a median follow-up of 61 months.

Results: Ninety-five patients (60.9%) died during follow-up. Higher baseline RDW levels were associated with all-cause mortality (unadjusted HR 1.35, 95%CI 1.20–1.52, P < 0.001). On multivariate analysis adjusted for clinical, electrocardiographic and laboratory variables, baseline RDW levels were associated with mortality (HR 1.33, 95%CI 1.16–1.53). RDW levels 6 months and 12 months post-implantation were also associated with mortality (HR 1.22, 95%CI 1.08–1.38, P = 0.001; and HR 1.15, 95%CI 1.01–1.32, P = 0.02, respectively). Patients who were re-admitted to hospital during follow-up (n=78) had higher baseline RDW levels as compared to those who were not (14.9%, IQR 14.0, 16.0% vs. 14.3%, IQR 13.7, 15.0%, respectively, P = 0.03). 

Conclusion: An elevated RDW level before and after CRT implantation is independently associated with all-cause mortality. 

 

Background: Defibrillation threshold (DFT) testing at the time of implantable cardioverter defibrillator (ICD) insertion is performed routinely. Recently this practice is being reconsidered due to doubts about its ability to improve ICD efficacy and evidence that survival may not be affected by the test.

Objectives: To compare the outcome of ICD recipients who underwent DFT testing and those in whom no testing was performed.

Methods: A total of 213 eligible patients were implanted with an ICD between 2004 and 2009. DFT testing was performed in 80. We compared total mortality, appropriate and inappropriate ICD shocks, and anti-tachycardia pacing (ATP) events between DFT and non-DFT patients during a follow-up of 2 years.

Results: On comparing the DFT and non-DFT groups, we found a 2 year mortality rate of 7.5% versus 8.3%, respectively (P = 0.8). Furthermore, 20.7% of patients in the DFT group and 12.4% in the non-DFT group had at least one episode of ICD shock (P = 0.15). With regard to ICD treatment (ICD shocks or ATP events), 57.7% in the DFT group and 64.2% in the non-DFT group received appropriate treatments (P = 0.78).

Conclusions: No significant differences in the incidence of 2 year mortality or percentage of ICD treatment emerged between the DFT and non-DFT groups.