Cost-effectiveness of genetic testing in family members of patients with long-QT syndrome.
BACKGROUND
Family members of patients with established long-QT syndrome (LQTS) often lack definitive clinical findings, yet may have inherited an LQTS mutation and be at risk of sudden death. Genetic testing can identify mutations in 75% of patients with LQTS, but genetic testing of family members remains controversial.


RESULTS
We used a Markov model to assess the cost-effectiveness of 3 strategies for treating an asymptomatic 10-year-old, first-degree relative of a patient with clinically evident LQTS. In the genetic testing strategy, relatives undergo genetic testing only for the mutation identified in the index patient, and relatives who test positive for the mutation are treated with β-blockers. This strategy was compared with (1) empirical treatment of relatives with β-blockers and (2) watchful waiting, with treatment only after development of symptoms. The genetic testing strategy resulted in better survival and quality-adjusted life years at higher cost, with a cost-effectiveness ratio of $67 400 per quality-adjusted life year gained compared with watchful waiting. The cost-effectiveness of the genetic testing strategy improved to less than $50 000 per quality-adjusted life year gained when applied selectively either to (1) relatives with higher clinical suspicion of LQTS (pretest probability 65% to 81%), or to (2) families with a higher than average risk of sudden death, or to (3) larger families (2 or more first-degree relatives tested).


CONCLUSIONS
Genetic testing of young first-degree relatives of patients with definite LQTS is moderately expensive, but can reach acceptable thresholds of cost-effectiveness when applied to selected patients.
Center for Inherited Cardiovascular Disease, Stanford University Medical Center, 300 Pasteur Drive, Stanford, CA 94305, USA. mvperez@stanford.edu
Marco V
MV
Perez
Narmadan A
NA
Kumarasamy
Douglas K
DK
Owens
Paul J
PJ
Wang
Mark A
MA
Hlatky
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D003362:Cost-Benefit Analysis; D005820:Genetic Testing / Q000191:economics*; D006801:Humans; D008133:Long QT Syndrome / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D008390:Markov Chains; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D057832:Watchful Waiting
D000319:Adrenergic beta-Antagonists