A new protocol for a single-stage combined cardiopulmonary and echocardiography exercise test: a pilot study

The value of cardiopulmonary exercise testing (CPET) and exercise stress echocardiography (ESE) in managing cardiac disease is well known, but no standard CPET-ESE protocol is currently recommended. This pilot study aims to compare feasibility and cardiac function responses between a new high-intensity single-stage combined test (CPET-hiESE) and a standard maximal ESE (smESE).

After screening and maximal CPET, all volunteers (n = 21) underwent three ESE modalities: (i) based on the gas exchange threshold (hiESE-GET, 40% of peak-GET, 6 min), (ii) based on heart rate (HR) (hiESE-HR, 80% of peak HR, 6 min), and (iii) smESE (85% of predicted peak HR for age, 3 min). Speckle tracking echocardiography (STE) and tissue Doppler imaging (TDI) were measured at each step. There was superior image quality and data completeness for the right ventricle strain for both hiESE modalities compared with smESE (71.4 and 76.2 vs. 42.9%, P = 0.07). Left ventricular STE data completeness was similar for all three conditions. Despite systematically higher HR, work rate and levels of exertion in the smESE compared with hiESE, STE and TDI parameters were not systematically different. Concordance correlation coefficients ranged from 0.56 to 0.88, lowest for strain rate parameters and mean difference from -0.34 to 1.53, highest for TDI measurements.

The novel CPET-hiESE protocol allowed for better data completeness, at lower levels of exertion compared with smESE, without systematically different cardiac reserve measurements in healthy participants. This single-stage protocol can be individualized to clinical populations, which would provide practical advantages to standard testing.