Background: Many well-conducted studies have shown that Cardiac Resynchronization Therapy (CRT) is a viable treatment for selected heart failure patients in terms of symptom relief, clinical improvement, decrease in hospital visits, and even in mortality. The conventional implantation technique consists in a classical right endocardial leads placement, and in a left ventricular lateral coronary vein implantation, through the coronary sinus os. Although the results seem nowadays satisfactory, there are definitively many drawbacks and complications associated to this technique, leading to poorer results than expected. In order to improve those results, a less invasive surgical technique has been developed in our institution since 2001. This report shows the retrospective results.
Material and Method: From June 2001 to December 2005, 77 consecutive patients have been receiving a CRT device; all had a conventional implantation of the right endocardial leads, and a surgical LV lead implantation with a left robotic-enhanced thoracoscopic approach. The LV lead position was pre-assessed with a transthoracic echocardiography. All patients had an indication for a CRT device, either a pacemaker (PM), or an implantable defibrillator cardioverter (ICD).
The response to CRT was defined as an improvement of at least one NYHA functional class. Adversely, all patients without improvement of the NYHA class and/or those who died during the first 6 post-operative months were considered as non responders.
Results: Mean follow up time was 20,4 months (0-56). At study completion, only one patient was lost to follow up after 21 months. The response rate in our series was 74 %. No correlation was found between the sex, the age, the NYHA class, the etiology, the type of device and the response to CRT. At 36 months, epicardial leads mean stimulation threshold was 2.4 Volts, mean sensing was 10,1 mVolts, and mean impedance was 756,8 Ohms. The median survival was within 34 to 56 months. No difference in survival was found between the PM group and the ICD group (p = 0,42). No difference in survival was observed between the ischemic and non ischemic patients (p = 0,37).
Conclusions: Based on our results we strongly believe that minimally invasive LV lead implantation for CRT has to be taken into account, not only as a backup therapy of the percutaneous approach, but certainly also as a first line technique in this selected HF group of patients. Our results strongly support the fact that placing more accurately the LV lead may contribute to better CRT results.