Abstract 17961: Conundrum of Sudden Death With a Psychiatric Diagnosis: Disease Process or Culprit Drug?
Introduction: Mechanisms of sudden cardiac death (SCD) in patients with a psychiatric diagnosis could be related to clinical risk factors/comorbidities, QT interval-prolonging therapeutic drugs or the disease process itself.
Hypothesis: Consideration of all 3 categories of variables in analyses will improve the understanding of SCD mechanisms.
Methods: SCD cases and controls ≥18 yrs were compared in an ongoing large, prospective community-based evaluation of SCD in the Northwestern US (Pop. approx. 1 million). Pearson’s chi-square and independent samples t-tests were used for univariate comparisons. Logistic regression was used to evaluate the effects of medications, psychiatric diagnoses, and corrected QT interval (QTc) on SCD risk while adjusting for age, gender, and clinical risk factors/comorbidities.
Results: Comparisons were conducted between 1384 SCD cases (66% males, 63.7± 4.0 yrs) and 761 controls (67% males, 66.4±10.9 yrs) controls. Cases had a higher prevalence of schizophrenia (p=0.001) and prolonged QTc (40 vs 14%, p<0.0001), and were more likely to use antidepressants (30 vs. 25%, p=0.03), antipsychotics (8 vs. 2%, p<0.0001), QT prolonging therapeutic agents (46 vs. 37%, p=0.0003) and opiates (26 vs. 19%, p=0.0002). Overall, QTc was significantly longer in cases (452±39 vs. 424±32, p<0.0001). Among cases, QTc was prolonged in the subset with bipolar disorder, and among those taking anti-psychotics, and anti-depressants (p≤0.002). In multivariable models, QTc remained associated with SCD after adjusting for age, gender, clinical risk factors/comorbidities, and medications, with every 20 ms unit-increase conferring 1.5-fold increased odds of SCD risk. Use of antipsychotics [OR 2.8 (1.3-6.1), p=0.01)] also remained associated with increased SCD risk, but anti-depressants and psychiatric diagnoses were no longer significant.
Conclusions: Therapeutic drug-related QTc prolongation remains a significant risk factor for SCD, with a complex interplay between drugs and psychiatric diagnoses that warrants ongoing investigative scrutiny.
- © 2013 by American Heart Association, Inc.