American College of Cardiology (ACC) 61st Annual Scientific Session & Expo

March 24-27, 2012; Chicago, IL
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Posters

Cardiac Resynchronization Therapy Combined With Defibrillator Prolongs Survival in Octogenarians
When added to an implantable cardioverter defibrillator (ICD), cardiac resynchronization therapy (CRT) prolongs survival in patients 80 years and older with heart failure, compared with use of an ICD alone. In a retrospective study, survival outcomes were similar between appropriately chosen CRT-ICD recipients aged 80 years and older as well as CRT-ICD recipients aged 70 to 79 years. These findings were presented at the ACC 61st Annual Scientific Session & Expo by researchers from the Heart and Vascular Institute, University of Pittsburgh, PA.

Outcomes data after CRT are limited among patients aged 80 years and older, the researchers note. In two large clinical trials, COMPANION (Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure) and CARE-HF (Cardiac Resynchronization—Heart Failure), the mean age of CRT recipients was approximately 66 years. Single-center studies from the Netherlands and the United Kingdom have shown that functional improvement and survival were not different between CRT recipients when these outcomes were dichotomized at various ages (70, 75, and 80 years).

Further, among three age groups (<60 years, 60-74 years, and ≥75 years) of patients enrolled in the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy), a trial conducted in patients with class I or II heart failure symptoms, a survival benefit with CRT was confined to patients in the two oldest age groups.

The authors analyzed outcomes of 499 consecutive patients with New York Heart Association class II to IV heart failure referred for CRT-ICD who were older than 70 years at the time of implantation; 163 of them were 80 years and older (range, 80-92 years). Among those 80 years and older, the baseline characteristics were similar between individuals who received CRT-ICD and those who received an ICD without CRT. In this age group, CRT-ICD recipients were nearly three times more likely to survive than ICD recipients over a mean follow-up of 38 months, with an uncorrected hazard ratio (HR) of 2.9 (P=.002) and an HR of 3.9 (P=.001) when controlling for age, sex, ischemic heart disease, diabetes, atrial fibrillation, renal function, and QRS duration.

When comparing CRT-ICD patients 80 years and older with those who were 70 to 79 years old, the latter group had a significantly higher incidence of diabetes (43% vs 26%; P=.001), a significantly greater left ventricular end-diastolic diameter (61 mm vs 57 mm; P<.001), and a significantly greater left ventricular end-systolic diameter (51 mm vs 46 mm; P<.001). Over a mean follow-up of 44 months, unadjusted survival was not different between the two groups (HR, 1.0) and no significant difference was observed in corrected survival (HR, 1.2; P=.13).

The oldest CRT-ICD recipients experienced functional improvement and reversal of ventricular remodeling comparable to that observed in their younger counterparts. On follow-up echocardiograms (≥6 months after CRT) in 152 patients, there was no difference in the improvement in left ventricular ejection fraction or the change in left ventricular end-systolic volume between recipients 80 years and older and those 70 to 79 years old.—Wayne Kuznar
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Epidemiologic Study Finds Link Between Atrial Fibrillation and Cancer in Older Adults

Incident cancer is more likely in patients 65 years and older who are hospitalized for atrial fibrillation (AF), compared with the general population, according to Italian researchers, who presented their finding during a poster session at the ACC 61st Annual Scientific Session & Expo. The authors hypothesized that AF is linked to noncardiac diseases because patients with AF have demonstrated features of chronic inflammation. In the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) study, an AF management strategy of rhythm control conferred no advantage over rate control on cardiac mortality or vascular mortality, but rhythm control was associated with an increase in the rate of noncardiovascular death, mainly attributable to pulmonary diseases and cancer (Circulation. 2004[16];109:1973-1980).

The Italian researchers analyzed the relationship between AF and cancer, identifying all patients hospitalized for AF between 2005 and 2007 in Florence, Italy. Prevalent cases of cancer were identified using the Tuscany Cancer Registry. Excluded from the analysis were persons who experienced an episode of AF or cancer in the previous 5 years.

The incidence of cancer was ascertained using the Tuscany Inpatient Registry, with further validation from the Tuscany Cancer Registry. Cases of prostate cancer and skin neoplasms other than melanoma were excluded from the analysis. Follow-up was closed in 2010. The standardized incidence ratio (SIR), which is the ratio between the observed and the expected number of cases of malignancies, was estimated for all new cases of cancer. Expected cases were computed using age- and sex-adjusted incidence rates of neoplastic disease.

Between 2005 and 2007, AF was recorded during 16,986 hospital admissions. In 4270 of those, AF was the primary diagnosis. Because some patients were hospitalized for AF more than once, the total number of subjects enrolled was 3323, and after exclusion of those with a history of cancer or with incomplete data, there were 1843 remaining for analysis.

Among the 1843 patients, 133 cases of cancer were identified in patients with AF, compared with an expected incidence of 88 (SIR, 1.51; P<.001). The incidence of cancer was significantly greater for both men and women with AF compared with their counterparts in the general population without AF. An analysis by age demonstrated that the influence of AF on the development of cancer became evident in subjects 65 years and older, a trend that was evident in both men and women. Stomach, kidney, and brain cancers were the most common cancers observed in the AF population.

—Wayne Kuznar