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Value of treadmill exercise test in pre- and postoperative children with valvular aortic stenosis
Insights
The graded treadmill exercise test (ETT) is less effective in assessing aortic stenosis severity in postoperative patients compared to nonoperated individuals. This impacts the accuracy of exercise testing for evaluating obstruction severity post-surgery.
Area of Science:
- Cardiology
- Exercise Physiology
Background:
- Aortic stenosis (AS) is a significant valvular heart disease.
- Postoperative assessment of AS severity is crucial for patient management.
- The utility of exercise testing in postoperative AS patients remains unclear.
Purpose of the Study:
- To evaluate the effectiveness of graded treadmill exercise test (ETT) in estimating aortic stenosis severity in postoperative patients.
- To compare ETT performance in postoperative AS patients versus a nonoperated AS group.
Main Methods:
- Retrospective comparison of postoperative AS patients and a nonoperated AS group.
- All patients underwent cardiac catheterization for gold standard assessment.
- ETT parameters were analyzed for sensitivity and specificity in identifying obstruction severity (peak systolic ejection gradient - PSEG) and elevated left ventricular end-diastolic pressure (LVEDP).
Main Results:
- ETT demonstrated lower sensitivity (67%) and specificity (63%) for identifying significant obstruction (PSEG ≥ 50 mmHg) in postoperative AS patients compared to nonoperated patients (100% sensitivity, 56% specificity).
- For detecting elevated LVEDP (≥ 12 mmHg), ETT showed reduced sensitivity (45%) and specificity (33%) in postoperative patients versus nonoperated patients (75% sensitivity, 100% specificity).
- No significant differences in baseline hemodynamic parameters were observed between the groups.
Conclusions:
- Graded treadmill exercise testing has diminished utility in accurately assessing aortic stenosis severity in patients after surgery.
- The accuracy of ETT for evaluating obstruction and associated hemodynamic changes is compromised in the postoperative setting.
- Alternative or adjunctive diagnostic methods may be necessary for comprehensive assessment of AS in these patients.
Abstract:
To determine the utility of graded treadmill exercise test (ETT) in estimating severity of obstruction in postoperative patients with aortic stenosis, we compared results to a nonoperated aortic stenosis group. Cardiac catheterization was performed in all patients. The interval between surgery and ETT in the postoperative group was 7.5 years (range 1.1-12.9). Mean and range values for postoperative versus nonoperative aortic stenosis groups respectively were: age 14.5 (7.9-20.8) versus 12.5 years (5.9-19.7); peak left ventricular pressure 150 (101-190) versus 144 mmHg (100-183); peak systolic ejection gradient (PSEG) 41 (15-75) versus 38 mmHg (14-80); left ventricular end-diastolic pressure (LVEDP) 13.4 (7-20) versus 13.5 mmHg (8-20); and cardiac index 3.7 (2.4-5.6) versus 3.8 liters/min/m2 (2.6-4.9) (p for each = NS). ETT in the nonoperated patients correctly identified all those with PSEG greater than or equal to 50 mmHg (sensitivity 100%), but specificity was 56%, (i.e., the proportion correctly identified with PSEG less than 50 mmHg). By contrast, sensitivity and specificity for postoperative aortic stenosis patients were 67% and 63%, respectively. Furthermore, among nonoperated aortic stenosis patients ST depression on ETT identified those with increased left ventricular end-diastolic pressure. For LVEDP greater than or equal to 12 mmHg, sensitivity was 75% and specificity 100%, corresponding values for postoperative aortic stenosis patients were 45% and 33%, respectively. In the nonoperated aortic stenosis group with a PSEG greater than or equal to 50 mmHg, sensitivity and specificity for ETT-induced change in systolic blood pressure of less than or equal to 30 mmHg were 100% and 56%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)