Renin-Angiotensin System Inhibitors Prognostic Benefit in Older Patients with Atrial Fibrillation

OBJECTIVES

Angiotensin-converting enzyme inhibitors (ACEi) and angiotensin-receptor blockers (ARB) have shown antiarrhythmic effects that are useful as part of the upstream therapy for atrial fibrillation (AF), both for primary and secondary prevention. Nevertheless, the potential prognosis value of these drugs in terms of mortality and major cardiovascular events is unclear, especially in older population with AF. Scientific evidence is scarce in this population and shows contradictory results. The aim of this study was to assess the potential benefit of ACEi and ARB in terms of mortality and major cardiovascular outcomes (hospitalization for heart failure, acute myocardial infarction and stroke) in older patients with AF, based on a real-world data analysis.

DESIGN

Observational: analysis of a retrospective registry.

SETTINGS AND PARTICIPANTS

The study included 9365 patients of 75 years or older diagnosed with AF, from CardioCHUVI-AF_75 registry: ClinicalTrials.gov Identifier: NCT04364516. Date of registration: November 26, 2018.

METHODS

We performed propensity score matching techniques to obtain 2 comparable groups of 3601 patients with and without ACEi or ARB treatment. We compared survival and cardiovascular outcomes in both groups of patients using Cox proportional hazards models.

RESULTS

We did not find significant differences in terms of survival between using or not using ACEi or ARB for the older population (hazard ratio for mortality: 0.959, 95% confidence interval 0.872-1.054). There were no significant differences regarding cardiovascular major events between the 2 groups.

CONCLUSIONS AND IMPLICATIONS

Treatment with ACEi or ARB did not improve outcomes in terms of survival and cardiovascular events in older patients with AF. These results should prompt the conduct of randomized clinical trials specifically in the older AF patient population to robustly address this issue.

Algorithm-based reduction of inappropriate defibrillator shock: Results of the Inappropriate Shock Reduction wIth PARAD+ Rhythm DiScrimination-Implantable Cardioverter Defibrillator Study

BACKGROUND

Inappropriate shocks (IS) continue to have a major negative impact on patients implanted with defibrillators.

OBJECTIVE

The purpose of this study was to assess IS reduction with the PARAD+ discrimination algorithm in a general population implanted for primary or secondary prevention.

METHODS

ISIS-ICD (Inappropriate Shock Reduction wIth PARAD+ Rhythm DiScrimination-Implantable Cardioverter Defibrillator) was a 2-year international, interventional study in patients implanted with a dual implantable cardioverter-defibrillator (ICD) or triple-chamber defibrillator (cardiac resynchronization therapy-defibrillator [CRT-D]) featuring PARAD+. IS (shocks not delivered for ventricular tachycardia or fibrillation) were independently adjudicated. The primary endpoint was percentage of IS-free patients at 24 months. Primary and worst-case analyses of annual incidence rates of patients with ≥1 IS, overall and per defibrillator type, were conducted.

RESULTS

In total, 1013 patients (80.7% male; age 67.1 ± 11.4 years; 68%/30%/2% primary/secondary/other indication) were enrolled and followed for a median of 552 days (interquartile range 354; 725). Of 993 analyzed patients programmed with PARAD+, 14 had ≥1 IS, corresponding to a percentage free from IS of 98.1% (95% confidence interval [CI] 96.8%- 98.9%). Annual incidence rates (per 100 person-years) of patients with IS were 1.0 (95% CI 0.59-1.69) and 2.1 (95% CI 1.46-3.02) in the primary and worst-case analyses, respectively. In ICD patients, rates were 1.2 (95% CI 0.68-2.23) and 2.3 (95% CI 1.47-3.53), and in CRT-D patients 0.59 (95% CI 0.19-1.83) and 1.8 (95% CI 0.93-3.44) per 100 person-years.

CONCLUSION

The annual rate of defibrillator patients with IS using the enhanced PARAD+ discrimination algorithm alone ranged from 1.0 to 2.1 per 100 person-years in a general population implanted for primary or secondary prevention.

Association of cardiac resynchronization therapy with the incidence of appropriate implantable cardiac defibrillator therapies in ischaemic and non-ischaemic cardiomyopathy

Aims

Cardiac resynchronization therapy (CRT) reduces the incidence of sudden cardiac death and the use of appropriate implantable cardioverter-defibrillator (ICD) therapies (AICDTs); however, this antiarrhythmic effect is only observed in certain groups of patients. To gain insight into the effects of CRT on ventricular arrhythmia (VA) burden, we compared the incidence of AICDT use in four groups of patients: patients with ischaemic cardiomyopathy vs. non-ischaemic dilated cardiomyopathy (NIDC) and patients implanted with an ICD vs. CRT-ICD.

Methods and results

We analysed 689 consecutive patients (mean follow-up 37 ± 16 months) included in the Umbrella registry, a multicentre prospective registry including patients implanted with ICD or CRT-ICD devices with remote monitoring capabilities in 48 Spanish Hospitals. The primary outcome was the time to first AICDT. Despite a worse clinical risk profile, NIDC patients receiving a CRT-ICD had a lower cumulative probability of first AICDT use at 2 years compared with patients implanted with an ICD [24.7 vs. 41.6%, hazard ratio (HR): 0.49, P = 0.003]; on the other hand, there were no significant differences in the incidence of first AICDT use at 2 years in ischaemic patients (22.6 vs. 21.9%, P = NS). Multivariate analysis confirmed the association of CRT with lower AICDT rates amongst NIDC patients (Adjusted HR: 0.55, CI 95% 0.35-0.87).

Conclusions

These data suggest that CRT is associated with significantly lower rates of first AICDT use in NIDC patients, but not in ischaemic patients. This study suggests that ICD patients with NIDC and left bundle branch block experiencing VAs may benefit from an upgrade to CRT-ICD despite being in a good functional class.