Cardiopulmonary exercise testing in transthyretin amyloid cardiomyopathy patients: a long-term follow-up study
Robin Willixhofer1, René Rettl1, Christina Kronberger1
1Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna.
Insights
Transthyretin amyloid cardiomyopathy patients initially improve in functional capacity but later decline. Peak oxygen consumption above 14 ml/kg·min and a ventilation to carbon dioxide slope below 40 indicate a better prognosis.
Area of Science:
- Cardiology
- Pulmonology
- Internal Medicine
Background:
- Transthyretin amyloid cardiomyopathy (ATTR-CM) significantly impairs patient functional capacity.
- Assessing functional capacity changes over time is crucial for managing ATTR-CM.
Purpose of the Study:
- To evaluate the longitudinal changes in functional capacity in ATTR-CM patients using cardiopulmonary exercise testing (CPX).
- To identify prognostic markers for ATTR-CM progression.
Main Methods:
- 34 ATTR-CM patients underwent serial CPX and blood tests at baseline, 8 months (V1), and 35 months (V2).
- Key CPX parameters analyzed included peak work capacity, peak oxygen consumption (VO2), and ventilation to carbon dioxide slope (VE/VCO2).
Main Results:
- Functional capacity, indicated by peak work capacity and peak VO2, improved at V1 but declined by V2.
- The VE/VCO2 slope increased significantly at V2, suggesting worsening cardiopulmonary function.
- A peak VO2 < 14 ml/kg·min and VE/VCO2 slope > 40 were associated with increased mortality and heart failure hospitalizations.
Conclusions:
- ATTR-CM patients exhibit short-term functional capacity improvement followed by long-term deterioration.
- Peak VO2 > 14 ml/kg·min and VE/VCO2 slope < 40 are favorable prognostic indicators in ATTR-CM.
Aims:
Patients with transthyretin amyloid cardiomyopathy (ATTR-CM) experience reduced functional capacity. We evaluated changes in functional capacity over extensive follow-up using cardiopulmonary exercise testing (CPX).
Methods:
ATTR-CM patients underwent CPX and blood testing at baseline, first [V1, 8 (6-10) months] and second follow-up (V2) at 35 (26-41) months after start of disease-specific therapy.
Results:
We included 34 ATTR-CM patients, aged 77 (±6) years (88.2% men). CPX showed two patterns with functional capacity improvement at V1 and deterioration at V2. Peak work capacity ( P = 0.005) and peak oxygen consumption (VO 2 , P = 0.012) increased at V1 compared with baseline and decreased at V2. The ventilation to carbon dioxide relationship slope (VE/VCO 2 ) increased at V2 compared with baseline and V1 ( P = 0.044). A cut-off for peak VO 2 at 14 ml/kg·min showed more events (composite of death and heart failure hospitalization): less than 14 vs. greater than 14 ml/kg·min ( P = 0.013). Cut-offs for VE/VCO 2 slope at 40 showed more events greater than 40 vs. less than 40 ( P = 0.009).
Conclusion:
ATTR-CM patients showed an improvement and deterioration in the short-term and long-term follow-up, respectively, with a better prognosis for those with peak VO 2 above 14 ml/kg·min and for a VE/VCO 2 slope below 40.
More Related Videos
Related Concept Videos
01:27Chronic Obstructive Pulmonary Disease-IV: Assessement and Diagnostic Studies
Medical History
01:30Cardiomyopathy II: Dilated Cardiomyopathy
01:29Cardiomyopathy III: Hypertrophic Cardiomyopathy
01:29Cardiomyopathy IV: Restrictive Cardiomyopathy
01:29Cardiomyopathy V: Interprofessional Care
01:29Cardiomyopathy VI: Nursing Management