title: Identification of Low-Risk Adult Congenital LQTS Patients.
abstract: BACKGROUND
  To date, most risk stratification studies in long-QT syndrome (LQTS) have focused on identification of high-risk subjects. Current data on the long-term clinical course of low-risk adult LQTS patients are limited.
  
  
  RESULTS
  Patients in this study were from the Rochester-based LQTS Registry. We hypothesized that long-term survival of LQT1-2 patients with QTc <500 milliseconds and no cardiac symptoms before age 20 (n = 523) would be similar to that of their unaffected genotype-negative family members (n = 1,134). Kaplan-Meier survival analysis and multivariate Cox proportional hazards regression models were used to evaluate the incidence and risk of all-cause mortality in the study population. The low-risk LQTS study group comprised 27% (523/1,919) of genetically confirmed LQTS Registry patients alive at age 20. The cumulative probability of all-cause mortality between age 20 and 65 was similar in the low-risk LQTS group and the genotype-negative control group (4.3% and 4.4%, respectively at age 65; P = 0.49 for overall difference). Multivariate analysis showed no significant difference in the risk of all-cause mortality between the 2 groups (HR = 0.89; 95% CI 0.33-2.43, P = 0.82). Consistent results were revealed in subgroup analyses in female and male LQTS patients and in patients with genetically identified LQT1 and LQT2 mutations.
  
  
  CONCLUSIONS
  We identified a sizeable proportion of low-risk, adult LQTS patients with no cardiac symptoms before age 20 and QTc<500 milliseconds who had 45-year survival similar to unaffected family members.
authors: Heart Research Follow-Up Program, University of Rochester Medical Center, Rochester, New York, USA.
authors: Claire
authors: C
authors: Zhang
authors: Heart Research Follow-Up Program, University of Rochester Medical Center, Rochester, New York, USA.
authors: Valentina
authors: V
authors: Kutyifa
authors: Heart Research Follow-Up Program, University of Rochester Medical Center, Rochester, New York, USA.
authors: Scott
authors: S
authors: McNitt
authors: Heart Research Follow-Up Program, University of Rochester Medical Center, Rochester, New York, USA.
authors: Wojciech
authors: W
authors: Zareba
authors: Heart Research Follow-Up Program, University of Rochester Medical Center, Rochester, New York, USA.
authors: Ilan
authors: I
authors: Goldenberg
authors: Heart Research Follow-Up Program, University of Rochester Medical Center, Rochester, New York, USA.
authors: Arthur J
authors: AJ
authors: Moss
mesh_terms: D000200:Action Potentials; D000328:Adult; D000368:Aged; D058070:Asymptomatic Diseases; D016009:Chi-Square Distribution; D004252:DNA Mutational Analysis; D005260:Female; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing / Q000379:methods*; D006329:Heart Conduction System / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D015994:Incidence; D051657:KCNQ1 Potassium Channel / Q000235:genetics*; D051658:KCNQ2 Potassium Channel / Q000235:genetics*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009154:Mutation; D009518:New York; D010641:Phenotype; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D029597:Romano-Ward Syndrome / Q000175:diagnosis* / Q000235:genetics* / Q000401:mortality / Q000503:physiopathology; D013997:Time Factors; D055815:Young Adult
chemical_list: D005819:Genetic Markers; D051657:KCNQ1 Potassium Channel; C496909:KCNQ1 protein, human; D051658:KCNQ2 Potassium Channel; C496914:KCNQ2 protein, human
keywords: congenital heart disease; genetic testing; insurance; long-QT syndrome