Abstract 13350: Improvement of Left Ventricular Diastolic Property is a Crucial Factor for Benefits from Cardiac Resynchronization Therapy
Background: Cardiac resynchronization therapy (CRT) can improve heart failure symptoms prior to left ventricular (LV) reverse remodeling. LV diastolic dysfunction is a condition leading to symptom, morbidity, hospitalizations and death, independently from LV systolic function. This study aimed to assess the changes of LV diastolic property by CRT.
Methods: One hundred three patients who had undergone CRT (LVEF 23±8%, QRS 166±39 msec) were studied with a GE Vivid 7. Left atrial volume and LV end-systolic volume were measured using the modified biplane Simpson's method and indexed to body surface area (LAVi and LVESVi, respectively). Both LAVi and pulmonary vascular resistance (PVR) were determined as a marker of LV diastolic property at baseline and 6 months of CRT. PVR was calculated as 80 multiplied by the ratio of peak tricuspid regurgitant velocity to the right ventricular outflow tract time-velocity integral. Responders to CRT were defined as improvement of at least one NYHA class 6 months after CRT, and LV reverse remodeling was defined as a decrease of LVESVi > 15%.
Results: Among 68 responders (66%), LV reverse remodeling was seen in 38 patients whose LAVi and PVR decreased from 74±28 to 54±25 ml/m2 (P<0.001) and from 214±78 to 163±52 dynes·sec·cm−5 (P=0.001), respectively. Both LAVi and PVR of the remaining 30 responders without LV reverse remodeling modestly but significantly decreased from 69±25 to 57±22 ml/m2 (P<0.001) and from 236±88 to 193±62 dynes·sec·cm−5 (P=0.01), respectively. In 35 non-responders, all of these parameters adversely increased. The incidence of cardiac events including death, heart failure readmission, VT/VF, and LV assist device implantation was significantly different among these groups (P<0.001, Figure).
Conclusions: The improvement of LV diastolic property is tightly linked to the response to CRT, and the degree of improvement is particularly remarkable in patients with LV reverse remodeling.
- © 2010 by American Heart Association, Inc.