Aims: Implantable cardioverter defibrillators (ICDs) are used for primary or secondary prevention of sudden cardiac death. We sought to clarify prognosis and causes of death after ICD implantation.
Methods and results: A total of 2743 patients with ICDs implanted during 1990-2020 were analyzed. Median age was 68.5 (59.6-74.6) years; 21% women, median left ventricular ejection fraction (LVEF) was 30 (23-35), 52% had an ischemic etiology and 77% had a primary preventive indication. Mortality rate after 10 years was 22, 44, 55, and 72% in the 1st, 2nd, 3rd, and 4th age quartile, respectively. The calculated median sex and age adjusted loss of life years compared to the average German population was 9.7 (6.1-14.0) years. Prognosis was independently related to sex, age, LVEF, and glomerular filtration rate. 713 out of 852 deaths could be classified to a specific cause. Congestive heart failure (CHF) accounted for death in 214 (30%) and sudden death (SD) for 144 patients (20%). Postmortem interrogation of devices in 74 patients revealed VT/VF in 39 and no episodes in 35 patients. Cancer was identified as the cause of death in 121 patients (17% of cases), of which 36 were bronchial carcinomas. 73 (10%) of patients died due to infection. 67 patients (9%) died within 24 h of procedures. Compared to other causes, significantly more life years were lost associated with procedures and SD: 9.3 (5.7-12.9) versus 12.1 (7.4-15.2) and 11.9 (7.6-17.8) years.
Conclusion: Life expectancy of ICD patients is lower than for the general population. Mortality is predominantly due to CHF, but there is still a considerable rate of SD. The occurrence of cancers, most importantly bronchial carcinomas, and infections, warrants protective measures. Some deaths during procedures are possibly preventable. Patients with ICDs comprise a vulnerable cohort, and treatment has to be optimized in many directions to improve prognosis.
Keywords: Cancer; Heart failure; Implantable cardioverter defibrillator; Infection; Procedures; Prognosis; Sudden death.