A novel “Response Score” predicts hemodynamic responders to cardiac resynchronization therapy

S82 Background and Objective: Coronary sinus (CS) access and pacing is not achieved in about 10% of patients (pts) in whom the cardiac resynchronization therapy (CRT) is required. The aim of this study was identify predictive factors for unsuccessful pacing from CS. Methods: The study was performed in 2 centers and included 211 consecutive pts refered for CRT between January 2000-October 2004, mean aged 71⫾8 years (71.6% men). Mean NYHA class was 3.2⫾0.6 , left ventricular ejection fraction 22.7⫾11.3%, LV end-diastolic diameter 75.4⫾8.6mm, LV end-systolic diameter 59.7⫾10.4mm, QRS duration 172.7⫾19.9 mseg, 6-min walk distance 259.6⫾141.2 metres and Quality of life score 40.6⫾18.5. The heart failure etiologies were ischemic in 89 pts (42.2%), idiopathic in 95 pts (45.0%) and valvular disease in 27 pts (12.8%). Permanent atrial fibrillation (AF) was present in 58 pts (26.0%). Results: Mean procedure time was 127⫾33 minutes (min), mean fluroscopy time 35.5⫾19.3 min, mean CS cannulation time 12.8⫾10.4 min and mean positioning time for lead 15⫾9 min. In 26 pts (12.6%) the attempt to pace from the CS was unsuccessful. At univariate analysis, a higher proportion of unsuccessful implants were observed among patients with permanent AF (30.5% vs 4.9%, p⬍0.001), valvular heart disease (26.3% vs 8.6%, p⫽0.023) and those with previous cardiac surgery (25.7% vs 6.0%, p⫽0.001). Anteroposterior, longitudinal and transversal left atrium diameters by echocardiography were higher among patients with an unsuccessful implant (55.6⫾9.8 vs 42.8⫾5.9 mm, p⬍0.001; 67.4⫾9.5 vs 52.4⫾6.8 mm, p⬍0.001; 59.4⫾7.8 vs 46.2⫾7.0 mm, p⬍0.001; respectively). At logistic regression analysis, the presence of permanent AF and anteroposterior left atrium diameter were independents predictors of failure implant (OR 7.7, 95% CI 2.5-21.9, p⫽0.002 and OR 4.8, 95% CI 1.2-6.8, p⫽0.001 respectively). Conclusions: In our study, the presence of permanent AF and the anteroposterior left atrium diameter were independents predictive factors for unsuccessful pacing from the CS. AB41-3 ATRIAL FIBRILLATION FURTHER IMPAIRS CARDIAC SYMPATHETIC RESPONSE TO BARORECEPTOR UNLOADING IN CONGESTIVE HEART FAILURE Paul A. Gould, FRACP, Murray Esler, MD, PhD and David Kaye, MD, PhD. Baker Heart Research Institute, Prahran, Australia and Baker Heart Research Institute, Australia. Background: Both elevated cardiac sympathetic activity and atrial fibrillation (AF) have been associated with increased mortality in congestive heart failure (CHF). The exact mechanism for AF is unclear. Cardiac adrenergic drive has previously been shown to be influenced by cardiac filling pressures. We hypothesised that AF and associated structural atrial changes may further impair cardiac sympathetic response to changes in filling pressures as assessed at head up tilt (HUT). Methods: We enrolled 18 CHF patients 9 in sinus rhythm (SR) and 9 in AF, age 59 ⫾ 2 years, ejection fraction 30 ⫾ 2 %. Patients underwent Swan-Ganz, arterial and coronary sinus catheter placement for the measurement of hemodynamics and cardiac sympathetic tone. Cardiac sympathetic tone was measured by calculating the veno-arterial trans-cardiac norepinephrine (NE) gradient and correcting for neural re-uptake by measuring extraction of tritiated (4H) NE across the heart. NE was measured using high performance liquid chromatography and electrochemical detection. The plasma (3H)-NE concentration was determined by liquid scintillation spectroscopy after collection of eluant from the electrochemical detector cell using a fraction collector. Parameters were measured at baseline and after 10 minutes of 20° and then 30° of passive HUT. Results: During HUT there was a significant fall in filling pressures in both SR (p ⬍ 0.001) and AF (p⫽ 0.002) groups. The cardiac sympathetic response to HUT however was significantly lower in AF compared with SR (p ⫽ 0.014, figure 1). Conclusion: In CHF, AF confers impairment of cardiac sympathetic response to baroreceptor unloading during HUT in comparison to SR possibly secondary to atrial remodelling. This finding provides insights into possible mechanisms for increased CHF mortality when complicated by AF.

Heart Rhythm, Vol 2, No 5, May Supplement 2005

AB41-4 A NOVEL “RESPONSE SCORE” PREDICTS HEMODYNAMIC RESPONDERS TO CARDIAC RESYNCHRONIZATION THERAPY E. Kevin Heist, MD, PhD, Cynthia Taub, MD, Dali Fan, MD, PhD, Daniel Arzola-Castaner, MD, Chrisfouad R. Alabiad, MD, Theofanie Mela, MD, *Jeremy N. Ruskin, MD, Michael H. Picard, MD and *Jagmeet P. Singh, MD, PhD. Massachusetts General Hospital, Boston, MA. Background: Cardiac resynchronization therapy (CRT) is an accepted treatment for congestive heart failure with ventricular dyssynchrony, but a substantial number of patients show no response to therapy. Objective: The purpose of this study is to develop a simple scoring system to predict hemodynamic responders to CRT. Methods: Of 101 consecutive patients undergoing CRT, all 38 with satisfactory echocardiographic assessment of contractility and LV dyssynchrony, intra-cardiac measurement of non-paced LV lead electrical delay as a percentage of QRS duration (LVLED) and post-procedural chest radiography (to determine LV-RV inter-lead distance) were included. Echocardiographic assessment of contractility was measured by Doppler analysis of mitral regurgitation as % change in dP/dt (⌬dP/dt) with CRT on and off. Hemodynamic responders to CRT were defined by ⌬dP/dtⱖ25%. Baseline LV dyssynchrony was measured by tissue Doppler imaging as the maximum time difference (MTD) between peak systolic velocity of anterior, septal, lateral and inferior walls. Results: Variables associated with ⌬dP/dt include (A) dorsal-ventral LV-RV lead separation (LV-RV dist) (r⫽0.46, p⫽0.004), (B) LVLED (r⫽0.36, p⫽0.02), (C) baseline dP/dt (r⫽-0.52, p⫽0.0007), and (D) MTD (r⫽0.61, p⫽⬍0.0001). Other variables, including baseline QRS width and LV lead proximity to hypokinetic regions, were not associated with ⌬dP/dt. A Response Score was generated assigning 1 point for each of the following: (A) LV-RV dist ⬎ 10cm, (B) LVLED ⱖ 50%, (C) baseline dP/dt ⬍ 600 mmHg/sec and (D) MTD⬎100ms. Response Score (0-4 points) was strongly associated with hemodynamic response to CRT (p⬍0.0001, see figure). Conclusion: A simple 4 point “Response Score” encompassing variables related to both patient selection and lead placement can accurately predict hemodynamic responders to cardiac resynchronization.