Effectiveness of resynchronisation therapy in pharmacological treatment-resistant patients with NYHA class III-IV heart failure

Alberto León-Martín A, Benezet-Peñaranda JM, Martínez Delgado C, Rodríguez-Martín JL

Objectives: To assess whether cardiac resynchronization therapy with single stimulation

or associated with defibrillation has any effect on pharmacological treatment-resistant

subjects with class III-IV heart failure, low ejection fraction (< 35%) and wide QRS (>

120 msec), using an systematic international review based on randomised clinical trials.

Method: Systematic search and review of relevant literature on cardiac resynchronization

in subjects with the above mentioned characteristics. Randomized controlled clinical

trials assessing the effectiveness of cardiac resynchronization therapy versus conventional

therapy were reviewed.

Results: Among 2417 references identified 2139 abstracts were selected; 896 being

considered potentially relevant; 62 studies fulfilled our inclusion criteria; and 10 of

them were included in the study.

Conclusions: Global mortality showed a relative reduction of risk of 29% (RR 0.71; 95%

CI 0.59 to 0.85) when comparing resynchronization with only pharmacological treatment.

On analysing mortality due to heart failure within the subanalysis of resynchronization

versus only pharmacological treatment as control group, a significant reduction

was found (37 mortality events in resynchronization group versus 66 in control group).

This difference in specific mortality should be interpreted as clinically relevant (RR 0.55;

95% CI 0.38 to 0.81). In patients with advanced heart failure a significant improvement

is observed in total, and specific mortality on comparing cardiac resynchronization with

conventional pharmacological treatment.

Alberto León-Martín A, Benezet-Peñaranda JM, Martínez Delgado C, Rodríguez-Martín JL