Defibrillator implantation for the primary prevention of sudden death in patients awaiting cardiac transplantation: one center's experience.

Patients who are on a waiting list for cardiac transplantation often have a clinical profile that satisfies current recommendations for the implantation of an implantable cardioverter-defibrillator for the primary prevention of sudden death. The prospect that transplantation may take place within the short-to-medium term puts the effectiveness of this therapy in doubt. We investigated the incidence of therapy delivered by implantable cardioverter-defibrillators implanted for primary prevention in patients awaiting cardiac transplantation. Recent changes in the incidence of sudden death at our center were also investigated. Data on 308 patients listed for heart transplantation between 1998 and 2008 were reviewed. An implantable cardioverter-defibrillator was indicated for primary prevention at initial evaluation in 17 patients. Of these, 53% received appropriate implantable cardioverter-defibrillator therapy while carrying an implantable cardioverter-defibrillator for a mean period of 7.8 months (±4.8). Only one patient received inappropriate therapy and none had any complications associated with device use. The frequency of sudden death has decreased over the course of recent years.

Comparison of baseline characteristics and survival between patients with idiopathic and connective tissue disease-related pulmonary arterial hypertension.

BACKGROUND: Both idiopathic pulmonary arterial hypertension (IPAH) and pulmonary arterial hypertension (PAH) related to connective tissue diseases (CPAH) are classified in the group of PAH disorders. However, CPAH has a particularly worse prognosis than IPAH. Few studies have compared the clinical, functional and hemodynamic profiles of IPAH and CPAH. METHODS: We performed a retrospective cohort study of patients with IPAH or CPAH. Demographic characteristics, functional status (FE), pulmonary function test and hemodynamic values at the time of diagnosis were compared between the two etiologies. Global cumulative survival rates free from transplantation (SFT) and survival according to date of diagnosis were analyzed. RESULTS: Despite similar PAH severity, patients with CPAH showed a more severe baseline impairment of 6-minute walking test (6MWT) (307 +/- 116 m vs 378 +/- 101 m) and diffusion capacity of the lung for carbon monoxide (DLCO) (57 +/- 25% vs 75 +/- 30% of predicted) than IPAH (p < 0.01). Survival rates at 1, 3 and 5 years of follow-up were 87%, 71% and 63% for IPAH, and 70%, 53% and 42% for CPAH, respectively (p < 0.05). IPAH showed better survival when treatment was started after Year 2000 (p = 0.01). However, CPAH showed a poorer prognosis than IPAH in the more recent era (p < 0.05). CPAH (hazard ratio [HR] = 2.03), DLCO <80% (HR = 1.98) and treatment before Year 2000 (HR = 2.27) were associated with an independent increased risk of death or transplantation. CONCLUSIONS: Despite similar functional and hemodynamic severity, patients with CPAH showed a more severe baseline impairment of 6MWT and DLCO and worse overall prognosis than IPAH. Both IPAH and CPAH survival improved in the current era. Nevertheless, CPAH still showed a poorer prognosis than IPAH.

Assessment of cardiac viability by thallium 201 redistribution and dobutamine echocardiography.

OBJECTIVE: Dobutamine echocardiography and thalium 201 are useful in the assessment of myocardial viability, but both techniques frequently yield conflicting results. The objective of this study was to determine the minimum mass of viable myocardium that each test could detect and compare the agreement of dobutamine echocardiography and thallium 201 to detect viability. METHODS: Dobutamine echocardiography and thallium 201 were performed in 10 patients scheduled for cardiac transplantation. In each patient, 15 segments were studied. After transplantation these segments were analyzed by the pathologist measuring by a computer system the total area of each segment, the necrotic + fatty mass, and area (%) of viable myocytes per segment. The percentage of viable tissue was estimated ([Total mass - (Necrotic + Fatty tissue)]/Total mass x 100) on each segment, which was compared with the result (viable or not viable) obtained by echocardiography or thallium 201. RESULTS: Dobutamine echocardiography defined 90 segments (60%) as viable versus 117 (78%) in thallium (kappa 0.49, 95% CI 0.36-0.63). The minimum percent of viable tissue per segment defined as viable by thallium was 43% versus 49% by echocardiography. With use of thallium, the highest accuracy of the test to detect viability was when the percent of necrotic tissue of the segment analyzed was 40% (positive and negative likelihood ratio 2.2 and 3.6, respectively). By use of echocardiography, the highest accuracy of the test was observed when the percent of necrotic tissue of the segment analyzed was 31% (positive and negative likelihood ratio 5.5 and 7.7, respectively). CONCLUSION: The discrepant results of dobutamine echocardiography and thallium 201 are due to differences in the minimum mass of live myocytes required by each technique to detect viability.