Abstract 3075: Impaired Right Ventricular Function should not exclude patients from consideration of Cardiac Resynchronization Therapy
Impaired right ventricular (RV) function is an important prognostic factor in heart failure. However it is not known how RV function influences response to cardiac resynchronisation therapy (CRT). Data from 128 pts were assessed at baseline and 6 months after CRT (pre-CRT: 67±0.9 y, EF: 23±1%, QRS width >130 ms, 63 (49 %) ischaemic aetiology). We defined two categories of response to CRT: clinical response, defined as a reduction in NYHA>1 class, and reverse remodelling, defined as a reduction in LV end-systolic volume >10%. RV function was assessed from M-mode ring excursion of the free wall and pts were subdivided into 4 groups: Normal (>20 mm), mildly reduced (15–20 mm), moderately reduced (10 –15 mm) and severely reduced (<10 mm) RV ring excursion. Pulmonary artery pressure (PAP) was measured as peak tricuspid regurgitation velocity + right atrial pressure. As shown in table 1⇓, 92 (72%) pts responded clinically to CRT. Reverse remodelling and clinical response was seen in 77 (60%) patients. In DCM patients, a high response rate (85%) was seen with preserved RV function. However, even with severe RV dysfunction, most DCM pts responded both clinically and echocardiographically. In ischaemic patients, no relationship was observed between overall (clinical or clinical plus remodelling) response and RV function, but the likelihood of remodelling was lower in each RV function group compared to DCM and may be dictated more by the extent of viable LV myocardium. PAP fell significantly (p<0.001) in responders but not non-responders after CRT.
Conclusion: Patients can respond to CRT even in the presence of severe RV dysfunction and should not be denied CRT if they fulfil the ESC/AHA criteria. Reverse remodelling is less in ischaemic patients irrespective of RV impairment.