Citations

Tomas Konecny, 2012 Finalist and Presenting Author

Introduction: Aortic dilatation has been associated with various cardiac conditions, although its prevalence and clinical correlates in hypertrophic cardiomyopathy (HCM) remains unclear. Hypothesis: We hypothesized that tubular ascending aorta dilatation would be common in a large referral population of patients with HCM. Furthermore, we hypothesized that aortic size would correlate with age and presence of left ventricular outflow tract obstruction. Methods: 1704 patients with HCM underwent echocardiographic measurement of the tubular ascending aorta during index evaluation at a tertiary HCM referral center. End-diastolic ascending aorta dimension was indexed to body surface area, with dilatation defined as two standard deviations above normal (>19 mm/m2). Aortic size and presence of aortic enlargement were correlated with clinical and echocardiographic parameters. Results: Aortic dilatation was present in 304 patients with HCM (18%). Indexed ascending thoracic aorta dimension was 16.5 (IQR 17.8-18.2) mm/m2 (Figure 1). Indexed dimension increased linearly with age (R=0.53, p<0.0001). Women and patients with a history of systemic hypertension were more likely to have aortic enlargement (29.8% vs 9.9% and 24.1% vs 10.6%, p<0.0001 for both). There was a correlation between resting left ventricular outflow tract gradient and indexed aortic dimension (R=0.12, p<0.0001) and patients with either resting (≥30 mmHg) or provocable obstruction (≥50 mmHg) were more likely to have aortic enlargement (19.6% vs 14.3%, p=0.006). Conclusions: In this large cohort of patients with HCM, aortic dilatation was common. Key correlates of aortic enlargement included age, female sex, history of hypertension and left ventricular outflow tract obstruction. Given an increased prevalence of aortic dilatation in HCM, further study is needed on the clinical impact of aortic dilatation.

Background Mitral regurgitation (MR) due to mitral valve prolapse (MVP) is often treatable by surgical repair. However, the very long-term (>10-year) durability of repair in both anterior leaflet prolapse (AL-MVP) and posterior leaflet prolapse (PL-MVP) is unknown. Methods and Results In 917 patients (aged 65±13 years, 68% male), surgical correction of severe isolated MR due to MVP (679 repairs and 238 replacements [MVRs]) was performed between 1980 and 1995. Survival after repair was better than survival after MVR for both PL-MVP (at 15 years, 41±5% versus 31±6%, respectively; P =0.0003) and AL-MVP (at 14 years, 42±8% versus 31±5%, respectively; P =0.003). In multivariate analysis adjusting for predictors of survival, repair was independently associated with lower mortality in PL-MVP (adjusted risk ratio [RR] 0.61, 95% CI 0.44 to 0.85; P =0.0034) and in AL-MVP (adjusted RR 0.67, 95% CI 0.47 to 0.96; P =0.028). The reoperation rate was not different after repair or MVR overall (at 19 years, 20±5% for repair versus 23±5% for MVR; P =0.4) or separately in PL-MVP ( P =0.3) or AL-MVP ( P =0.3). However, the reoperation rate was higher after repair of AL-MVP than after repair of PL-MVP (at 15 years, 28±7% versus 11±3%, respectively; P =0.0006). From the 1980s to the 1990s, the RR of reoperation after repair of AL-MVP versus PL-MVP did not change (RR 2.5 versus 2.7, respectively; P =0.58), but the absolute rate of reoperation decreased similarly in PL-MVP and AL-MVP (at 10 years, from 10±3% to 5±2% and from 24±6% to 10±2%, respectively; P =0.04). Conclusions In severe MR due to MVP, mitral valve repair compared with MVR provides improved very long-term survival after surgery for both AL-MVP and PL-MVP. Reoperation is similarly required after repair or replacement but is more frequent after repair of AL-MVP. Recent improvement in long-term durability of repair suggests that it should be the preferred mode of surgical correction of MVP whether it affects anterior or posterior leaflets and is an additional incentive for early surgery of severe MR due to MVP.

Background: Apical hypertrophic cardiomyopathy (apical HCM) is a less common subtype of HCM characterized by a focal thickening in the left ventricular apex. “Classic” ECG features have been described, however, apical HCM can persist for many years without detection. We investigated the relationship between ECG findings and echocardiographic morphometry in a large referral series of patients with apical HCM. Methods: We enumerated all patients diagnosed with apical HCM prior to Sept. 30, 2006 using the Mayo Clinic HCM database. We compared echocardiographic measures separately for patients with positive status for two ECG indices of left ventricular hypertrophy (LVH); the Sokolow-Lyon index and the Romhilt-Estes (RE) point-score. We also compared echocardiographic measurements in patients with and without negative T-waves in the precordial leads. Results: Apical HCM was detected in 177 patients (111 men and 68 women). Only 51% had positive Sokolow criteria and 51% had positive RE criteria. The agreement between Sokolow and RE status was high (agreement = 75.0%; kappa = 0.50; 95% CI = 0.38 – 0.62). In particular, Sokolow positive patients had increased LV ejection fraction (P = 0.02), and decreased LV end-systolic diameter (P = 0.03) compared with Sokolow negative patients. The prevalence of right atrial enlargement (47 vs. 28%; P = 0.02) and intracavity obstruction (22 vs. 8%; P = 0.01) were more common in Sokolow positive patients. Positive RE criteria was associated with a greater thickness of the basal septal and basal posterior walls (P = 0.001 and 0.02, respectively), and with a higher frequency of intracavity obstruction (21 vs. 9%; P = 0.04). Most patients (89%) exhibited at least one negative T-wave in the precordial leads; however, only 10% of patients had a negative T-wave of greater than 1.0 mV. We found that patients with an inverted T-wave larger than 0.4 mV (median) had a significantly increased LV ejection fraction (P = 0.03) compared with patients who had smaller or no negative T-waves. Conclusions: Among patients with apical HCM, nearly half do not have ECG evidence of LVH based on classic criteria and most do not have marked T-wave inversions. However, the majority did have at least a mild expression of negative T-waves.

Background. Apical hypertrophic cardiomyopathy (AHCM) has been considered a ``benign” form of HCM in Asian and non-Asian patients (pt). However, data on long-term outcome of pt with AHCM are limited. The purpose of this study was to determine the natural history of pt with AHCM followed at a tertiary referral center in North America. Methods. Between July 1976 and September 2006, 193 pt with the diagnosis of AHCM were seen at the Hypertrophic Cardiomyopathy Clinic. The last echocardiographic exam was reviewed in all pt. Follow-up data were obtained where possible (clinic visit). Results. Mean age at diagnosis 56±17 years, mean age at first presentation at our center was 58±17 years. Symptoms included chest pain in 69 pt (36 %), and exertional dyspnea ≥NYHA II in 97 pt (50 %). A family history of either HCM and/or sudden cardiac death was reported by 36 pt (19 %). Coronary artery disease was proven in 40 pt (21 %). Median follow up was 50 months (1–318) and obtained in 124 pt (64 %). The following events were reported at the last clinic visit: heart failure in =5 pt, syncope in =0 pt, ventricular tachycardia in =7 pt, ICD implantation in 22 pt, and stroke in 22 pt. Death from all causes occurred in 51 of 193 pt (26 %) at a mean age of 72 years (14–78). Kaplan-Meier survival analysis was used to examine survival from all causes of death since first presentation. Observed survival in patients with AHCM was significantly less than expected in an age- and gender matched Minnesota white population (p=0.009). The observed survival at 5, 10 and 15 years was 87 %, 82 %, and 57 % respectively, while the expected survival for these time points was 91 %, 81 %, and 72 %. Conclusions. AHCM in this predominantly North American patient population is associated with an increased mortality. Patients with AHCM have a high incidence of significant cardiovascular symptoms and ventricular arrhythmias. As the disease is less benign than previously suspected, careful longitudinal care by a cardiologist is warranted.

Background: Myocardial late gadolinium enhancement (LGE) on Contrast-Enhanced Magnetic Resonance Imaging (CE-MRI) of patients (pts) with hypertrophic cardiomyopathy (HCM) may indicate intra-myocardial fibrosis. We explored whether the presence and extent of LGE on CE-MRI among pts with HCM predicted ventricular arrhythmogenicity, and decreased survival. Methods: 424 HCM pts [age = 55 ± 16 years (range 2 – 90), 41% females], without prior history of septal ablation/myectomy, underwent CE-MRI (GE 1.5T) during a 6-year period. We compared the presence and amount of LGE with degree of ventricular ectopy on Holter ECG (available in 220 pts) recorded during the same time period of the CE-MRI. All cause death and appropriate, VF-terminating ICD therapies were then recorded during a mean follow-up of 34 ± 14 months (range 7 – 85). Results: 239 pts (56%) had LGE ranging from 0.4 – 65% of the myocardium. LGE -positive pts were more likely to have non-sustained ventricular tachycardia on Holter ECG [34/126 (27%) vs 8/94 (8.5%), p < 0.001], and had more total ventricular extrasystoles/24 hours (700 ± 2080 vs 103 ± 460, p < 0.001). During follow-up, 7 pts died and 4 received appropriate ICD discharges (9.7% of 41 pts with ICD). All 11 pts were LGE-positive. Event free survival was excellent (100%) in pts without LGE, and lower (95.4%) in pts with LGE (log rank, p < 0.002). Multivariate analysis (adjusting for age, gender, morphologic and functional data, and comorbidities) identified LGE involving ≥ 5% of LV mass (p=0.03, present in 7/11 pts with events), septal thickness≥30mm (p=0.03), and atrial fibrillation (p=0.02) as independent predictors of death or appropriate ICD discharges. Conclusions : In pts with HCM, LGE by CE-MRI was strongly associated with surrogates of arrhythmia and was independently associated with subsequent death and/or ICD discharge. If replicated, LGE may be considered a major risk for sudden death in HCM.

Background: Contrast enhanced magnetic resonance imaging (CE-MRI) is a useful tool to define cardiac morphology, systolic function, and the presence of late gadolinium enhancement (LGE). In patients (pts) with hypertrophic cardiomyopathy (HCM), LGE may represent intra-myocardial fibrosis. We explored the association between left ventricular (LV) morphology and function to the presence and amount of LGE in pts with HCM. Methods: 424 HCM pts (age = 55 ± 16 years, 41% females), without prior history of septal ablation/myectomy, underwent CE-MRI (GE 1.5T) during a 6-year period. LV volumes, diameter, ejection fraction (EF), septal shape and thickness, and the presence of obstructive physiology were assessed from standard steady state free precession pulse sequences. The presence and amount of LGE were traced from a dynamic post contrast inversion recovery pulse sequence. Morphologic and functional findings were then compared with presence and amount of LGE. Results: Over half of the pts [239/424 (56%)] had LGE, most commonly localizing to RV insertion points [174/239 pts, (73%)]. The extent of LGE ranged from 0.4–65% of LV mass. Univariate (morphologic) predictors of LGE were: reverse curve septal shape [OR = 7.8, (95% CI, 3.9–15.6)], septal thickness ≥ 16 mm (OR = 4.5, 2.4–8.2), LV mass ≥ 150 grams (OR = 2.6, 1.7–3.8)], LVEF<50% (OR = 4.6, 1.3–16), and presence of obstructive physiology (OR = 1.8, 1.02–3). The percentage of LV mass involved with LGE increased with higher LV mass, increased septal wall thickness, and decreasing LVEF (Spearman rank = 0.2– 0.4, p<0.0001 for all). Multivariate analysis (adjusting for all morphologic and functional parameters) showed that septal thickness ≥ 16mm (p = 0.0001), LV mass ≥ 150 grams (p = 0.01) and LVEF < 50% (p = 0.02) were independent predictors of LGE on CE-MRI. Conclusions: LGE, as determined by CE-MRI, was seen in over half of the patients with HCM. Decreased LVEF, increased septal thickness, and increased LV mass were associated with the presence of LGE. The clinical and prognostic impact of these morphological features warrants further investigation.