Author + information
- Sergey Kachura,b,
- Amy McNeala,b,
- Alban DeSchuttera,b,
- Carl Laviea,b,
- Ross Arenaa,b and
- Richard Milania,b
Background: An association between increasing cardio-respiratory fitness (CRF) and improved survival is well established. Absolute increases in CRF have been found to be an independent predictor in decreasing mortality risk. Here we examine an optimum threshold of CRF improvement in order to find “Super-Responders”, and what baseline traits are associated with this group.
Methods: 1110 subjects with stable CHD referred for cardiac rehabilitation (CR) between 01/2000 and 06/2013 with a mean follow-up of 6.3 years were analyzed using ROC to find the point of maximal sensitivity and specificity for predicting mortality. Mortality from the cohort was analyzed with respect to change in CRF with CR, as well as body mass index (BMI), initial CRF, age, ejection fraction, and sex. Logistic regression was performed on the super-responder group (SGG; N=446) to determine significant associations.
Results: ROC analysis of ΔCRF as a test for mortality yielded a threshold of +2.85 mLO2.kg-1.min-1 maximal oxygen consumption (VO2) (sensitivity 75.4%, specificity 46.5%). Dividing patients at this threshold resulted in mortality of 7.2% for the SGG, 17.2% for low-responders, and 23% for non-responders (p < 0.001 using ANOVA). In multi-variate analysis, the SGG has a significantly lower mortality association than both low- and non-responder groups (HR 0.51, p < 0.001; HR 0.3, p < 0.001, respectively). Make-up of SGG cohort was associated with being younger, an absence of depression, male sex, lower baseline lean mass and CRF (p < 0.05 for all).
Conclusions: Patients who achieve an increase in CRF in excess of 2.85 mLO2.kg-1.min-1 after CR have an independent association with increased survival in comparison with those who achieve less improvement. Surprisingly, this group has lower baseline lean mass and CRF, which contradicts the previously established beneficial associations with mortality of these independent factors. Future work should focus on the interplay between these factors and their effects on mortality.
Poster Hall, Hall C
Friday, March 17, 2017, 3:45 p.m.-4:30 p.m.
Session Title: Measuring Success in Cardiac Rehabilitation
Abstract Category: 34. Prevention: Rehabilitation
Presentation Number: 1147-041
- 2017 American College of Cardiology Foundation