Acute contractile recovery extent during biventricular pacing is not associated with follow-up in patients undergoing resynchronization.
BACKGROUND
It has been reported that contractility, as assessed using dobutamine infusion, is independently associated with reverse remodeling after CRT. Controversy, however, exists about the capacity of this approach to predict a long-term clinical response. This study's purpose was to assess whether long-term CRT clinical effects can be predicted according to acute inotropic response induced by biventricular stimulation (CRT on), as compared with AAI-VVI right stimulation pacing mode (CRT off), quantified at the time of implantation.


METHODS
In 98 patients (ejection fraction 29 ± 10%), acute changes in left ventricular (LV) elastance (Ees), arterial elastance (Ea), and Ees/Ea, as assessed from slope changes of the force-frequency relation obtained when the heart rate increased, and also assessed while measuring triplane LV volumes and continuous noninvasive blood pressure, were related to death or rehospitalization during a 3-year follow-up. Other covariances tested were age, gender, disease etiology, QRS duration, amount of mitral regurgitation, LV diastolic volume, ejection fraction, and the degree of asynchrony and longitudinal strain at baseline.


RESULTS
There was a marked increment in the Ees slope with CRT (interaction P = 0.004), no Ea change, and modest Ees/Ea increase (interaction P < 0.05). In Cox analysis, however, neither slope changes nor baseline values of Ees, Ea, and Ees/Ea were associated with long-term follow-up. Only ventricular diastolic volume (direct relation P = 0.002) and QRS duration (inverse relation P = 0.009) predicted death/rehospitalization.


CONCLUSIONS
Acute contractile recovery in CRT patients is not associated with 3 years prognosis. Instead, death or rehospitalization can be predicted from QRS duration and LV diastolic volume at baseline.
['DeVecchi|Federica|F|', 'Facchini|Emanuela|E|', 'Degiovanni|Anna|A|', 'Sartori|Chiara|C|', 'Cavallino|Chiara|C|', 'Santagostino|Matteo|M|', 'Di Ruocco|Virginia|V|', 'Magnani|Andrea|A|', 'Occhetta|Eraldo|E|', 'Marino|Paolo Nicola|PN|']
Resynchronization CRT, biventricular stimulation Congestive heart failure DYS, dyssynchrony Dyssynchrony EDV, end-diastolic volume EF, ejection fraction Ea, arterial elastance Ees, ventricular elastance FFR, force–frequency relation Force–frequency relation HR, hazard ratio LV, left ventricle MR, mitral regurgitation Speckle-tracking echocardiography TUS, temporal uniformity of strain r2, adjusted r squared