The investigations of predictors of success or failure of cardiac resynchronization therapy (CRT) were studied previously. But assessment of success in patients already on dual or single pacemakers and upgraded to CRT were not extensively studied before. How to select patients in whom this may be the most optimal strategy is unclear. We sought to determine factors associated with success or failure in this group of patients who were already paced for heart block. 81 pts were subjected to upgrade to CRT implantation after being on pacemaker. The study was conducted in Germany. Data was presented as Median (Min. – Max.) for abnormally distributed data or Mean ± SD. for normally distributed data. Parameters that revealed no statistical significance in response: Age, sex, EF, diabetes, renal disease, GFR, MR, QRS duration (all above 150 msec), AF and CRT optimization. The following parameters revealed significant influence on response to CRT: Less responders with: Higher CRP, presence of TR, presence of PHN, presence of previous MI, being ischemic vs nonischemic cardiomyopathy (less responders with ischemic CM). EF improved in responders from 30+8.6 to 39.86+9.77. The findings through light on specific parameters that predict response to upgrade to CRT after usual pacemaker. It confirms the benefit of upgrading to CRT from DDD or VVI in patients with EF less than 35%.
 

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