Patients with CS and ICDs are at high risk for ventricular arrhythmias. This population also has high rates of inappropriate shocks and device complications.

In this retrospective study, patients with isolated CS had very high rates of appropriate ICD therapy. Prospective, long-term follow-up of consecutive patients with isolated CS is needed to determine the true natural history and rates of ventricular arrhythmias in this rare and difficult-to-diagnose disease.

Background Sudden cardiac death (SCD) due to ventricular tachyarrhythmias accounts for approximately 450,000 annual deaths in the U.S.; many of these cases involve patients with chronic heart failure (HF). Prediction of which HF patients are most susceptible to SCD is difficult, and it is uncertain whether gene polymorphisms associated with HF outcomes are also linked to arrhythmic risk. Methods We evaluated 485 patients with chronic HF to see whether the Angiotensin Receptor Type 1 (AT1) A1166C or Angiotensin Converting Enzyme Insertion/Deletion (ACE I/D) polymorphisms were associated with a higher rate of ventricular arrhythmias requiring implantable cardioverter defibrillator (ICD) therapies over a 5-year period. We assessed the correlation between polymorphisms and antitachycardia pacing (ATP) and/or ICD shocks. Results Patients with AT1-1166 CC genotype had an increased rate of all events: ATP plus ICD shocks (p=0.02). There was no association between ACE I/D genotype and ICD therapies. Furthermore, circulating levels of microRNA-155 (miR-155), a microRNA known to posttranscriptionally regulate AT1R expression, were significantly decreased in the CC compared to the AC and AA genotypes and were associated with ICD events. Conclusion Our study suggests that the AT1R-1166 CC genotype is associated with increased ICD therapies in patients with chronic HF, and the level of circulating miR-155 may be a potential marker for arrhythmic risk. While these findings are novel, they will need replication and validation in larger cohorts of chronic HF patients.

Background. Peripheral arterial disease (PAD) often coexists with congestive heart failure (CHF) and can be masked by symptoms of CHF such as functional limitation (FL), a common manifestation for both. Therefore, we sought to estimate the prevalence of PAD and its independent association with FL in CHF. Methods. We conducted a cross-sectional study on National Health and Nutrition Examination Survey (NHANES) data from 1999 to 2004 to quantify weighted prevalence of CHF and PAD. Study cohort consisted of 7513, with ankle brachial index (ABI) measurements at baseline. Independent association of PAD (ABI ≤ 0.9) with FL in CHF was determined with multivariate logistic regression (MVLR). Results. Overall weighted PAD prevalence was 5.2%. CHF was present in 305 participants, and the weighted prevalence of PAD in this subgroup was 19.2%. When compared, participants with CHF and PAD were more likely to be older (P < 0.001), hypertensive (P = 0.005) and hypercholesterolemic (P = 0.013) than participants with CHF alone. MVLR showed that PAD (adjusted OR = 5.15; 95% CI: 2.2, 12.05: P < 0.05) and arthritis (adjusted OR = 2.36; 95% CI: 1.10, 5.06: P < 0.05) were independently associated with FL in CHF. Conclusion. Independent association of PAD with FL suggests the need for reinforced screening for PAD in individuals with CHF.