SAN FRANCISCO—Long-term anticipated and unanticipated device-related complications occur more frequently with cardiovascular resynchronization therapy defibrillator (CRT-D) therapy compared with either single- or biventricular implantable cardioverter defibrillator (ICD) therapy, according to study results presented May 6 at this annual Heart Rhythm Society (HRS) meeting.
“CRT is an established treatment for patients with moderately or severe symptomatic heart failure (HF) and evidence of ventricular dyssynchrony,” offered Maurizio Landolina, MD, of Fondazione Policlinico S. Matteo IRCCS in Pavia, Italy, and principal investigator of the study.
However, he explained that the long-term data on device-related events in patients receiving ICD therapy for CRT-D are sparse.
Landolina offered that the aim of the current study was to “quantify the frequency of repeat invasive procedures and the nature of long-term complications and patient outcomes.”
To do so, Landolina and colleagues conducted the Italian ClinicalService project that evaluated data from 3,253 patients who received successful CRT-D therapy at 117 Italian cardiovascular centers. Follow-up was 18 months.
The researchers conducted in-hospital follow-up exams and CRT-D was evaluated as well as its integrity and appropriate functioning. The researchers also reported clinical outcomes including hospitalizations and death.
The study’s primary endpoint was all device related adverse events. CRT-D was evaluated by comparing events that occurred in the CRT-D with the events that occurred in patients who underwent de novo implantation of single- or dual-chamber ICDs.
Landolina reported that events were reported in 416 patients. Surgical interventions were necessary in 390 patients and there were 220 unanticipated events (device-related infection or lead dislodgement) that required surgical intervention in 210 patients.
Four years after implantation 50 percent of patients underwent surgical intervention for device-related events and 15 percent of patients experienced unanticipated events. Landolina reported that there were 30 device-related infections, 120 cases of lead dislodgements, 51 lead malfunctions and seven prophylactic lead replacements.
Left ventricular lead dislodgements were reported at a rate of 2.3 per 100 patient-years, the researchers found. Additionally, device-related adverse events were found to be linked with worse clinical outcomes.
“CRT-D demonstrated higher rates of events then single- or dual chamber ICDs,” Landolina noted. “The vast majority of these events were due to battery depletion.
Device-related infections in CRT-D infections occurred at a rate of 1 percent and risk of infections increased after device replacement procedures."
According to the results, 167 patients died or underwent urgent heart transplant. Landolina offered that battery depletion represented the main cause of surgical revision in CRT-D patients (40 percent at four years).
Landolina concluded that in the future clinicians should inform patients “not only about possible procedure risks but about the risk of surgical revisions during follow-up.”