Passive Leg Raising Correlates with Future Exercise Capacity after Coronary Revascularization

Abstract

Hemodynamic properties affected by the passive leg raise test (PLRT) reflect cardiac pumping efficiency. In the present study, we aimed to further explore whether PLRT predicts exercise intolerance/capacity following coronary revascularization. Following coronary bypass/percutaneous coronary intervention, 120 inpatients underwent a PLRT and a cardiopulmonary exercise test (CPET) 2–12 days during post-surgery hospitalization and 3–5 weeks after hospital discharge. The PLRT included head-up, leg raise, and supine rest postures. The end point of the first CPET during admission was the supra-ventilatory anaerobic threshold, whereas that during the second CPET in the outpatient stage was maximal performance. Bio-reactance-based non-invasive cardiac output monitoring was employed during PLRT to measure real-time stroke volume and cardiac output. A correlation matrix showed that stroke volume during leg raise (SVLR) during the first PLRT was positively correlated (R = 0.653) with the anaerobic threshold during the first CPET. When exercise intolerance was defined as an anaerobic threshold < 3 metabolic equivalents, SVLR / body weight had an area under curve value of 0.822, with sensitivity of 0.954, specificity of 0.593, and cut-off value of 1504·10-3mL/kg (positive predictive value 0.72; negative predictive value 0.92). Additionally, cardiac output during leg raise (COLR) during the first PLRT was related to peak oxygen consumption during the second CPET (R = 0.678). When poor aerobic fitness was defined as peak oxygen consumption < 5 metabolic equivalents, COLR / body weight had an area under curve value of 0.814, with sensitivity of 0.781, specificity of 0.773, and a cut-off value of 68.3 mL/min/kg (positive predictive value 0.83; negative predictive value 0.71). Therefore, we conclude that PLRT during hospitalization has a good screening and predictive power for exercise intolerance/capacity in inpatients and early outpatients following coronary revascularization, which has clinical significance.

Short-term intensive training attenuates the exercise-induced interaction of mono-1/2 cells and platelets after coronary bypass in cardiac patients

“…The subjects underwent maximal graded exercise tests on a bicycle ergometer (Ergoselect 150P, Bitz, Germany) to assess their aerobic fitness and exercise haemodynamics after training. A submaximal stress test was also performed in the SIT and CT groups, in which the endpoint was supra-VAT (supra-ventilation anaerobic threshold) (▶ Figure 2) (16). Each subject was instructed to refrain from vigorous exercise or caffeine for 24 hours (h) before the test.…”

“…The reason why the SIT group did not have a better peak VO 2 than the CT group after training is because the SIT group had a worse baseline aerobic fitness, as indicated by VO 2 AT. Therefore, the SIT program may be used in an appropriate milieu or with those with a poor functional outcome (16).…”