COMPARISON OF EXERCISE PERFORMANCE IN PATIENTS WITH CHRONIC SEVERE HEART-FAILURE VERSUS LEFT-VENTRICULAR ASSIST DEVICES

Background-Left ventricular assist devices (LVADs) are frequently used as a bridge to cardiac transplantation and may be useful as long-term therapy. The purpose of this study was to compare the exercise perfor mance of LVAD patients with that of ambulatory heart failure patients. Methods and Results-Exercise testing with hemodynamic and respiratory gas measurements was performed in 65 congestive heart failure (CHF) p atients (age 53 +/- 10 years) and 20 LVAD patients (age 49 +/- 8 years ). Peak (V) over dot O-2, was significantly higher in the LVAD than th e CHF patients (CHF, 12 +/- 3; LVAD, 15.9 +/- 3.8 mL.kg(-1).min(-1); P <0.001), as was the (V) over dot O-2 at the anaerobic threshold (CHF, 8.1 +/- 2.1; LVAD, 12.2 +/- 2.9 mL.kg(-1).min(-1); P<0.001). At rest, mean arterial blood pressure (CHF, 87 +/- 11; LVAD, 94 +/- 9 mm Hg) an d cardiac output (CHF, 4 +/- 1; LVAD, 4.9 +/- 0.9 L/min) were increase d, whereas mean pulmonary artery pressure (CPIF, 28 +/- 11; LVAD, 18 /- 4 mm Hg) and pulmonary artery wedge pressure (CHF, 16 +/- 10; LVAD 5 +/- 3 mmHg) were reduced tall P<0.01). At peak exercise, heart rate (CHF,125 +/- 24; LVAD, 148 +/- 24 bpm), blood pressure (CHF, 87 +/- 14 ; LVAD,96 +/- 12 mm Hg), and cardiac output (CHF, 7.6 +/- 2.2; LVAD, 1 1.2 +/- 2.6 L/min) were higher tall P<0.01), whereas mean pulmonary ar tery pressure (CPIF, 48 +/- 12; LVAD, 30 +/- 5 mm Hg) and mean pulmona ry capillary wedge pressure (CHF, 31 +/- 11; LVAD, 14 +/- 6 mm Hg) wer e lower in the LVAD group (both P<0.001). In the LVAD patients, Fick c ardiac output was higher than LVAD flow sensor value measurements (Fic k, 11.6 +/- 2.5; LVAD, 8.1 +/- 1.2 L/min; P<0.001), Conclusions-Hemody namic measurements at rest and during exercise are significantly impro ved in patients with devices compared with those in ambulatory heart f ailure patients awaiting cardiac transplantation. Similarly, the exerc ise capacity of device patients is better than that of transplant cand idates and in the majority of patients is similar to that of patients with mild CHF.