Cardiac resynchronization therapy complications

Synonyms and Keywords: CRT
 * : Bhaskar Purushottam, M.D. [mailto:bpurushottam@gmail.com]

Overview
Bleeding, infection and lead dislodgement are not uncommon complications of cardiac resynchronization therapy.

Common Complications

 * 1) Bleeding and Hematomas: The incidence in clinical trials is 2.4%; in routine clinical practice, the actual incidence of pocket hematomas is probably higher as the trials only reported those hematomas, which needed surgical intervention. It is important to note that early re-intervention of pocket hematomas is associated with a 15-fold increase in infection.
 * 2) Infection
 * 3) Lead dislodgement. (CRT trials demonstrated a rate verying from 2.9% to 10.6%; the MIRACLE-ICD study demonstrated a higher occurence of lead dislodgement with left ventricular lead than right atrial and right ventricular leads-6.8%, 15 and 0.6% respectively).

Rare Complications

 * 1) Pneumothorax (0.9% in CRT trials, Medicare registry reported 1.2%),
 * 2) Myocardial injury
 * 3) Coronary sinus dissection (1.3%) or perforation (1.3%)(complication rate related to coronary veins has been reported in 2%)
 * 4) Pericardial tamponade.
 * 5) Pocket erosion
 * 6) Lead fracture
 * 7) Inappropriate phrenic nerve stimulation: Given the proximity of the posterior wall of the left ventricle to the phrenic nerve, there remains the risk of inappropriate phrenic nerve stimulation.

Mortality
For CRT patients, the average in-hospital mortality is 0.3% and the 30 day mortality is 0.7%. Reynolds et al. showed a 1.1% in-hospital mortality in 30,984 Medicare patients undergoing CRT. This disparity in the in-hospital mortality rates can be explained by the strict inclusion criteria of the trials, where the selected patients are healthier than the unselected patients in clinical practice.