The effect of revascularization on mortality and risk of ventricular arrhythmia in patients with ischemic cardiomyopathy.

BACKGROUND: There is clear evidence that patients with prior myocardial infarction and a reduced ejection fraction benefit from implantation of a cardioverter-defibrillator (ICD). It is unclear whether this benefit is altered by whether or not revascularization is performed prior to ICD implantation. METHODS: This was a retrospective cohort study following patients who underwent ICD implantation from 2002 to 2014. Patients with ischemic cardiomyopathy and either primary or secondary prevention ICDs were selected for inclusion. Using the electronic medical record, cardiac catheterization data, revascularization status (percutaneous coronary intervention or coronary bypass surgery) were recorded. The outcomes were mortality and ventricular arrhythmia. RESULTS: There were 606 patients included in the analysis. The mean age was 66.3 ± 10.1 years, 11.9% were women, and the mean LVEF was 30.5 ± 12.0, 58.9% had a primary indication for ICD, 82.0% of the cohort had undergone coronary catheterization prior to ICD implantation. In the overall cohort, there were fewer mortality and ventricular arrhythmia events in patients who had undergone prior revascularization. In patients who had an ICD for secondary prevention, revascularization was associated with a decrease in mortality (HR 0.46, 95% CI (0.24, 0.85) p = 0.015), and a trend towards fewer ventricular arrhythmia (HR 0.62, 95% CI (0.38, 1.00) p = 0.051). There was no association between death or ventricular arrhythmia with revascularization in patients with primary prevention ICDs. CONCLUSION: Revascularization may be beneficial in preventing recurrent ventricular arrhythmia, and should be considered as adjunctive therapy to ICD implantation to improve cardiovascular outcomes.

Tidal peritoneal dialysis versus ultrafiltration in type 1 cardiorenal syndrome: A prospective randomized study.

BACKGROUND: Ultrafiltration is an alternative strategy to diuretic therapy for the treatment of patients with acute decompensated heart failure. Little is known about the efficacy and safety of peritoneal dialysis in patients with acute decompensated heart failure complicated by acute cardiorenal syndrome. METHODS: We randomly assigned a total of 88 patients with type 1 acute cardiorenal syndrome to a strategy of ultrafiltration therapy (44 patients) or tidal peritoneal dialysis (44 patients). The primary endpoint was the change from baseline in the serum creatinine level and left ventricular function represented as ejection fraction, as assessed 72 and 120 h after random assignment. Patients were followed for 90 days after discharge from the hospital. RESULTS: Ultrafiltration therapy was inferior to tidal peritoneal dialysis therapy with respect to the primary endpoint of the change in the serum creatinine levels at 72 and 120 h (p = 0.041) and ejection fraction at 72 and 120 h after enrollment (p = 0.044 and p = 0.032), owing to both an increase in the creatinine level in the ultrafiltration therapy group and a decrease in its level in the tidal peritoneal dialysis group. At 120 h, the mean change in the creatinine level was 1.4 ± 0.5 mg/dL in the ultrafiltration therapy group, as compared with 2.4 ± 1.3 mg/dL in the tidal peritoneal dialysis group (p = 0.023). At 72 and 120 h, there was a significant difference in weight loss between patients in the ultrafiltration therapy group and those in the tidal peritoneal dialysis group (p = 0.025). Net fluid loss was also greater in tidal peritoneal dialysis patients (p = 0.018). Adverse events were more observed in the ultrafiltration therapy group (p = 0.007). At 90 days post-discharge, tidal peritoneal dialysis patients had fewer rehospitalization for heart failure (14.3% vs 32.5%, p = 0.022). CONCLUSION: Tidal peritoneal dialysis is a safe and effective means for removing toxins and large quantities of excess fluid from patients with intractable heart failure. In patients with cardiorenal syndrome type 1, the use of tidal peritoneal dialysis was superior to ultrafiltration therapy for the preservation of renal function, improvement of cardiac function, and net fluid loss. Ultrafiltration therapy was associated with a higher rate of adverse events.

The Effect of Shock Burden on Heart Failure and Mortality.

BACKGROUND: Prior studies have demonstrated an association between appropriate implantable cardioverter defibrillator (ICD) shocks and mortality in clinical trials. The effect of shock burden on heart failure and mortality has not been previously studied in a large population-based cohort. METHODS: The cohort was derived using a comprehensive prospective ICD registry in the province of Nova Scotia with a mean follow-up of 4 ± 2.3 years. With the use of time-varying analysis, the relationship among shock burden, mortality, and heart failure hospitalization was determined. RESULTS: A total of 776 patients (mean age of 64.8 years) were included in the study, of whom 37% received appropriate therapy during follow-up. A single ICD shock did not confer an increased mortality risk compared with no therapy (hazard ratio [HR], 1.23; 95% confidence interval [CI], 0.84-1.79; P = 0.3), but mortality risk was significantly increased with ≥ 2 shocks (HR, 3.23; 95% CI, 2.04-5.09; P < 0.0001). There was a significant increase in heart failure hospitalization associated with receiving 1 ICD shock (HR, 2.05; 95% CI, 1.46-2.89; P < 0.0001) or more than 1 ICD shock (HR, 4.36; CI, 2.53-7.52; P < 0.0001) compared with patients receiving no ICD therapy. Patients who received antitachycardia pacing alone showed no difference in heart failure hospitalization (HR, 0.93; CI, 0.67-1.29; P = 0.7) and improved survival (HR, 0.69; CI, 0.5-0.96; P = 0.03) compared with those receiving no ICD therapy. CONCLUSION: Ventricular arrhythmia treated with appropriate ICD shocks is associated with an increased risk of heart failure hospitalization, whereas recurrent episodes of ventricular arrhythmia requiring shocks are associated with both higher mortality and higher heart failure hospitalization rates.

CONTEXTE: Des études menées antérieurement ont révélé l'existence d'un lien entre l'administration appropriée de décharges électriques au moyen d'un défibrillateur cardioverteur implantable (DCI) et la mortalité au cours des essais cliniques. L'effet de telles décharges sur l'insuffisance cardiaque et la mortalité n'avait encore jamais été étudié au sein d'une cohorte d'envergure représentative de la population. MÉTHODOLOGIE: La cohorte a été établie au moyen d'un registre prospectif exhaustif des DCI implantés chez des patients de la Nouvelle-Écosse ayant fait l'objet d'un suivi moyen de 4 ± 2,3 ans. La relation entre le fardeau imposé par les décharges, la mortalité et l'hospitalisation pour insuffisance cardiaque a été déterminée au moyen d'une analyse en fonction du temps. RÉSULTATS: Au total, 776 patients (âge moyen : 64,8 ans) ont été admis dans l'étude; 37 % d'entre eux avaient reçu un traitement approprié au cours de la période de suivi. Une seule décharge délivrée par un DCI n'augmentait pas le risque de mortalité par rapport à l'absence de traitement (rapport des risques instantanés [RRI] de 1,23; intervalle de confiance [IC] à 95 %, de 0,84 à 1,79; p = 0,3), mais le risque de mortalité était significativement accru chez les patients ayant reçu ≥ 2 décharges (RRI de 3,23; IC à 95 %, de 2,04 à 5,09; p < 0,0001). Le risque d'hospitalisation pour insuffisance cardiaque s'est révélé significativement supérieur chez les sujets ayant reçu 1 décharge par DCI (RRI de 2,05; IC à 95 %, de 1,46 à 2,89; p < 0,0001) ou plus de 1 décharge par DCI (RRI de 4,36; IC à 95 %, de 2,53-7,52; p < 0,0001), comparativement à ceux n'ayant reçu aucun traitement par DCI. On n'a observé aucune différence quant à l'hospitalisation pour insuffisance cardiaque (RRI de 0,93; IC à 95 %, de 0,67 à 1,29; p = 0,7) et à l'amélioration de la survie (RRI de 0,69; IC à 95 %, de 0,5 à 0,96; p = 0,03) chez les patients qui ont reçu uniquement une stimulation antitachycardie comparativement à ceux qui n'ont reçu aucun traitement par DCI. CONCLUSION: L'arythmie ventriculaire traitée de façon appropriée au moyen de décharges électriques délivrées par un DCI est associée à un risque accru d'hospitalisation pour insuffisance cardiaque, tandis que des épisodes récurrents d'arythmie ventriculaire exigeant un traitement par décharge électrique sont associés à des taux supérieurs de mortalité et d'hospitalisation pour insuffisance cardiaque.

The influence of sex and age on ventricular arrhythmia in a population-based registry.

BACKGROUND: Post-hoc analyses of clinical trials and population-based studies have shown no difference in mortality between men and women, but often show that men are more likely to receive appropriate ICD therapy. We utilized a population-based registry to investigate the interaction of sex and age and the occurrence of ventricular arrhythmia in an ICD population. METHODS AND RESULTS: A total of 776 consecutive patients receiving an ICD for primary or secondary prevention in a provincial ICD registry were studied. No significant mortality difference was found between men and women (27.5% versus 23.7%, p=0.39). Overall, men were more likely to receive appropriate ICD therapy compared to women (39.3% versus 26.7%, p=0.006). The hazard ratio for appropriate therapy in men vs. women <60years of age was 3.22, CI 95% (1.56-6.65), p=0.002, and the same comparison in men vs. women over the age of 60 showed no significant difference (HR 1.11, CI 95% [0.74-1.65], p=0.61). This interaction between age and sex remained significant when adjusted for New York Heart Associated Class, ejection fraction, coronary artery disease and indication for ICD (p=0.02). CONCLUSIONS: This study demonstrates that the risk of appropriate ICD therapy increases as women are older, reaching similar risk as men in that age group. Further study of the mechanism of the interaction of age and sex as they modulate the occurrence of ventricular arrhythmia may be warranted.