Evaluation of Left Ventricular Hypertrophy in U.S. Air Force Aviators Daniel LaMar, MD, MPH Maj, USAF, MC, FS USAF School of Aerospace Medicine WPAFB, OH RAM 2013 Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 1
Disclosure Information 84th Annual Scientific Meeting Dr. Daniel LaMar I have no financial relationships to disclose. I will not discuss off-label use and/or investigational use in my presentation. Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 2
Outline Background Methods Demographics Results Discussion Limitations Questions Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 3
Background We currently use ECG on routine initial flying class physicals to screen for many conditions There have been many recommendations for cardiovascular screening for sports physicals Some recommend a routine ECG due to its ability to find hypertrophic cardiomyopathy Others recommend no ECG due to cost associated with screening and prevalence of condition Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 4
Background (cont.) In evaluating left ventricular hypertrophy (LVH), there has been little work done on young, healthy patients There has also been little done to look at ECG sensitivity to find LVH in these patients Without a good understanding of the sensitivity of ECG for LVH, it is difficult to make appropriate recommendations This study evaluated ECG use for LVH screening Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 5
Methods Used military flight screening database 20,955 people getting initial flight physical for USAF pilot training Subjects had both 12-lead ECG and echocardiogram performed All ECGs and echos evaluated by staff cardiologist at the USAF Aeromedical Consultation Service (ACS) Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 6
Methods (cont.) All ECGs coded for LVH if S in V1 or V2 + R in V5 or V6 was >55 mm (modified Sokolow Lyon criteria) Echocardiograms evaluated interventricular septal (IVS) thickness LVH on ECG was compared to LVH on echocardiogram using multiple values for IVS thickness Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 7
Demographics Male Female Average age 23.33 years 22.53 years African American 455 (2.4%) 39 (0.2%) Asian/Pacific Islander 416 (2.2%) 59 (0.3%) Caucasian 15386 (80.4%) 1457 (7.6%) Hispanic 702 (3.7%) 60 (0.3%) Other 509 (2.7%) 47 (0.2%) Total 17468 (91.3%) 1662 (8.7%) Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 8
Results IVS 1.1 cm LVH on Echocardiogram LVH on ECG Yes No Yes 52 (0.2%) 100 (0.4%) No 5,068 (24.2%) 15,735 (75.2%) Total 5,120 (24.4%) 15,835 (75.6%) IVS 1.3 cm LVH on Echocardiogram LVH on ECG Yes No Yes 5 (<0.1%) 147 (0.7%) No 450 (2.2%) 20,353 (97.1%) Total 455 (2.2%) 20,500 (97.8%) Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 9
Results (cont.) IVS 1.4 cm LVH on Echocardiogram LVH on ECG Yes No Yes 1 (<0.1%) 151 (0.7%) No 84 (0.4%) 20,719 (98.9%) Total 85 (0.4%) 20,870 (99.6%) IVS 1.5 cm LVH on Echocardiogram LVH on ECG Yes No Yes 0 (0%) 152 (0.7%) No 25 (0.1%) 20,778 (99.2%) Total 25 (0.1%) 20,930 (99.9%) Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 10
Results (cont.) IVS 1.1 cm IVS 1.3 cm IVS 1.4 cm IVS 1.5 cm Sensitivity 1.02% 1.10% 1.18% 0% Specificity 99.37% 99.28% 99.28% 99.27% PPV 34.21% 3.29% 0.66% 0% NPV 75.64% 97.84% 99.60% 99.88% Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 11
Results Cont. No cases of LVH found to have HCM Looked at echos with IVS 1.5 cm and all with significantly thickened septum showed appropriate regression with abstention of exercise Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 12
Discussion In young healthy UPT candidates, ECG is poorly sensitive for LVH (regardless of IVS thickness used to define LVH) Results can likely be extrapolated to adolescent sports physicals Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 13
Limitations Low percentage of females High percentage of Caucasians No cases of HCM in this study ECGs not recorded electronically, so no practical way to use different criteria for LVH Does not speak to other reasons for using ECGs in routine pilot training exams Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 14
ACS Database Our other database with 4,728 different people with echocardiograms and ECGs demonstrated similar results LVH on ECG gave 5-8% sensitivity for LVH on echo in a population having abnormal ECG or PE This was in an older population with greater prevalence of LVH on echo and much greater risk for LVH Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 15
Bibliography Halkin A, Steinvil A, Rosso R, et al. Preventing sudden death of athletes with electrocardiographic screening: what is the absolute benefit and how much will it cost? J Am Coll Cardiol 2012;60:2271-6. doi:10.1016/j.jacc.2012.09.003 Pewsner D, Jüni P, Egger M, et al. Accuracy of electrocardiography in diagnosis of left ventricular hypertrophy in arterial hypertension: systematic review. BMJ 2007;335:711. doi:10.1136/bmj.39276.636354.ae Rowin EJ, Maron BJ, Appelbaum E, et al. Significance of false negative electrocardiograms in preparticipation screening of athletes for hypertrophic cardiomyopathy. Am J Cardiol 2012;110:1027-32. doi:10.1016/j.amjcard.2012.05.035 Schoenbaum M, Denchev P, Vitiello B, et al. Economic evaluation of strategies to reduce sudden cardiac death in young athletes. Pediatrics 2012;130:e380-9. doi:10.1542/peds.2011-3241 Sheikh N, Cox A, Sharma S. Support for inclusion of electrocardiography in addition to the Health Questionnaire and Physical Examination in athletic screening protocols for diagnosis of unsuspected hypertrophic cardiomyopathy. Am J Cardiol 2013;111:150. doi:10.1016/j.amjcard.2012.10.002 Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 16
Questions? Distribution A: Approved for public release; distribution is unlimited. Case Number: 88ABW-2013-2037, 30 Apr 2013 17