The Prevalence and Association of Exercise Test Abnormalities With Sudden Cardiac Death and Transplant-Free Survival in Childhood Hypertrophic Cardiomyopathy

Figures

• 

  Figure 1.. All-cause mortality or transplant. A, Kaplan-Meier analysis showed that, compared with those with normal exercise stress test (EST) results (n=406; blue), 5-year transplant-free survival (all-cause mortality or transplant) was lower in those with an abnormal exercise test result (n=159; red; 97% vs 88%; P=0.005 by log-rank test). B, Kaplan-Meier analysis showed a difference in transplant-free survival by type of exercise-induced abnormality (P=0.0016). Compared with those with normal EST results (dashed black), 5-year transplant-free survival was lower for those with exercise-induced ischemia (orange; 79%; hazard ratio, 4.86 [95% CI, 1.69–13.99]; P=0.003) and those with an abnormal blood pressure response (red; 87%; hazard ratio, 3.19 [95% CI, 1.32–7.71]; P=0.01). There were no deaths or heart transplants in the exercise-induced ectopy-only category (green).

• 

  Figure 2.. Sudden cardiac death or aborted sudden cardiac arrest. A, Kaplan-Meier analysis showed no difference in 5-year freedom from sudden cardiac death (SCD) or aborted sudden cardiac arrest (SCA) between patients with normal exercise stress test (EST) results (n=396; blue) and those with abnormal exercise test results (n=154; red; 95% vs 88%; P=0.220). B, Kaplan-Meier analysis showed a difference in SCD event-free survival by type of exercise-induced abnormality (P=0.007). Compared with those with normal exercise testing results (dashed black), 5-year SCD event-free survival was lower for those with exercise-induced ischemia (orange; 71%; hazard ratio, 4.02 [95% CI, 1.57–10.28]; P=0.004). Five-year SCD event-free survival for those with abnormal blood pressure response (red; 91%) was not different from those with normal exercise test results. There were no SCD events in the exercise-induced ectopy-only subgroup (green). C, In the subset of patients with primary prevention implantable cardioverter defibrillator (ICD) implantation after an exercise test (n=165), 5-year freedom from appropriate ICD discharges was lower for those with abnormal exercise test results (n=69; red) compared…

• 

  Figure 3.. Other deaths or transplant. A, Kaplan-Meier analysis showed that compared with those with normal exercise stress test (EST) results (n=406; blue), 5-year freedom from other deaths or transplant was lower in the abnormal exercise test results group (n=159; red; 98% vs 91%; P=0.004 by log-rank test). B, Kaplan-Meier analysis showed a difference in outcome by type of exercise-induced abnormality (P=0.004). Compared with those with normal exercise test results (dashed black), 5-year freedom from other deaths or transplant was lower for those with exercise-induced ischemia (orange; 79%; hazard ratio, 7.64 [95% CI, 2.42–24.08]; P=0.001) and for those with an abnormal blood pressure response (red; 92%; hazard ratio, 3.33 [95% CI, 1.12–9.91]; P=0.031). There were no deaths or heart transplants in the exercise-induced ectopy-only subgroup (green). SCD indicates sudden cardiac death.

• 

  Figure 4.. Competing outcomes of sudden cardiac death vs other deaths or transplant. A, The 5-year cumulative proportion of death or transplant from the time of the exercise stress test (EST) was significantly higher among patients with an abnormal test result (red) compared with those with normal test results (blue; 8.9% vs 2.3%; log-rank P=0.004). B, Competing outcomes analysis showing the 5-year cumulative incidence of sudden cardiac death (SCD; black) and other deaths or transplant (purple) for patients with an abnormal exercise test result. C, Competing outcomes analysis showing the 5-year cumulative incidence of SCD (black) and other deaths or transplant (purple) for patients with a normal exercise test result. The 5-year cumulative incidence of SCD was not different between those with abnormal vs normal exercise test results (3.4% vs 1.1%, respectively; Gray test P=0.48). The 5-year cumulative incidence of other causes of death or transplant was higher for those with an abnormal vs normal test results (8.9% vs 0.6%, respectively; Gray test P=0.004).