Long term results of cardiac resynchronisation therapy for patients with severe heart failure
Bulava, A.; Lukl, J.; Hutyra, M.; Marek, D.
Vnitrni Lekarstvi 53(11): 1153-1163
2007
ISSN/ISBN: 0042-773X PMID: 18277624 Document Number: 606636
Cardiac resynchronisation therapy (CRT) has been shown to be a highly effective treatment strategy for patients with severe chronic heart failure (ChHF). To determine the clinical response of patients to CRT, to measure morbidity and mortality for this population of patients, to determine causes and predictors of death. To test whether the parameters of tissue Doppler echocardiography are able to predict response to CRT. Before and after implantation of the CRT and 12 months later, echocardiograph tests were carried out and relevant clinical data was recorded during the monitoring of patients. 102 patients (71 men, 31 women) with an average age of 71 +/- 9 years took part in the study. 68% patients had cardiac ischemia, 29% had idiopathic dilated cardiomyopathy. 75% patients were in functional class NYHA III, 25% NYHA IV. After a monitoring period of 711 +/- 329 days, 26 patients had died and 35 patients had been hospitalised. 34% of all hospitalisations were for acute exacerbation of ChHF. Patients with initial functional classification NYHA IV had a higher mortality rate in years one and two than patients in class NYHA III. The proportion of clinical responders was 64% after 12 months of CRT. In 58% of patients, a year of CRT produced a relative increase in the ejection fraction of the left ventricle (EF LV) of > or = 30%. 1/3 of patients had EF LV ? 45% with minimal symptoms of ChHF. The following were found to predict reverse remodelling of the left ventricle: less advanced state of the basic illness (EFLV > 23%, left ventricular end-diastolic diameter < 65 mm, left ventricular end-diastolic volume < 160 ml and left ventricular end-systolic volume < 120 ml) and interventricular mechanical delay > 45 ms. CRT is a safe method with a high success rate. There continues to be a problem with identifying responders. Symptoms of less advanced heart disease and interventricular delay were identified as sensitive predictors of the response to treatment.