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A new diagnostic algorithm for assessment of patients with single ventricle before a Fontan operation
Ashwin Prakash1, Muhammad A Khan, Rose Hardy
1Division of Pediatric Cardiology, Columbia University College of Physicians and Surgeons, New York, NY, USA. ashwin.prakash@cardio.chboston.org
Insights
A new algorithm effectively identifies children unsuitable for Fontan operations, avoiding invasive cardiac catheterization. This noninvasive approach accurately screens patients, improving diagnostic yield and predicting outcomes.
Area of Science:
- Pediatric Cardiology
- Cardiovascular Surgery
- Diagnostic Imaging
Background:
- Cardiac catheterization has limited diagnostic value before Fontan operations.
- Noninvasive imaging like MRI and CT are viable alternatives to invasive angiography.
Purpose of the Study:
- To propose and evaluate a novel diagnostic algorithm to identify "low-risk" subjects for Fontan operations, aiming to avoid routine cardiac catheterization.
- To assess the algorithm's efficacy in screening for inoperable subjects and predicting adverse postoperative outcomes.
Main Methods:
- A retrospective analysis of 151 children undergoing evaluation for Fontan operation.
- The algorithm identified "high-risk" subjects based on medical history, echocardiography, and noninvasive angiography.
- Conventional angiography results were used to validate the algorithm's performance.
Main Results:
- The algorithm classified 37% of subjects as "high-risk" and 63% as "low-risk".
- All 9 inoperable subjects were correctly identified as high-risk.
- The algorithm showed 51% sensitivity and 78% specificity in predicting adverse outcomes in patients who underwent the Fontan operation.
Conclusions:
- The proposed algorithm effectively screens candidates for Fontan procedures, identifying those unsuitable for surgery.
- Omitting preoperative invasive hemodynamic assessment did not compromise the prediction of adverse postoperative outcomes.
- Prospective studies are needed to validate this noninvasive diagnostic strategy before Fontan operations.
Objectives:
Cardiac catheterization has a low diagnostic yield before a Fontan operation, and magnetic resonance imaging and computed tomography are reliable alternatives to invasive angiography. A new diagnostic algorithm to avoid cardiac catheterization in "low-risk" subjects before a Fontan operation is proposed.
Methods:
The proposed algorithm would identify "high-risk" subjects on the basis of risk factors on medical history, echocardiography, and noninvasive angiography. The efficacy of this algorithm in screening for subjects deemed to be inoperable after catheterization was evaluated retrospectively in 151 children. For this analysis, results of conventional angiography (assumed to be equivalent to noninvasive angiography) were used.
Results:
According to the algorithm, 95 (63%) of 151 subjects had no risk factors ("low risk") whereas 56 (37%) of 151 had 1 risk factor or more ("high risk"). Nine (6%) of 151 subjects were found to be inoperable after catheterization and all 9 were correctly classified as high risk by the algorithm. In the 135 of 151 subjects who underwent a Fontan operation, the algorithm predicted an adverse postoperative outcome with a sensitivity of 51% and specificity of 78%. However, this prediction was not improved by including elevated pulmonary artery pressure or ventricular filling pressure as additional risk factors.
Conclusions:
The proposed algorithm effectively screened for subjects who were deemed unsuitable for a Fontan procedure. In addition, omitting preoperative invasive hemodynamic assessment did not impair prediction of adverse postoperative outcomes. Prospective evaluation of such a noninvasive diagnostic strategy before the Fontan operation is warranted.
