Mitral annular calcification in obstructive hypertrophic cardiomyopathy: Incidence, risk factors, and prognostic value after myectomy.

BACKGROUND: Mitral annular calcification (MAC) is a risk factor for cardiac surgery, but there is limited study on the prognosis value and the impact for valve function of MAC based on computed tomography (CT) diagnosis after myectomy for hypertrophic obstructive cardiomyopathy (OHCM). METHODS: Consecutive OHCM patients underwent septal myectomy were compared according to the existence of MAC and its severity in preoperative CT scans. The survival data were evaluated and compared by Kaplan Meier analysis and log rank test. Cox regression analysis was used to evaluate the impact of MAC on endpoint events. RESULTS: From the entire cohort of 1035 patients, 10.8% had MAC. In multivariate regression, female (OR = 2.23), age (OR = 1.07), aortic annular calcification (OR = 2.52), aortic calcification (OR = 2.56), systolic anterior motion of the mitral valve (SAM) (OR = 0.42), mitral valve thickening (OR = 2.13), and tricuspid regurgitation (OR = 3.12) were independent predictors of MAC. All-cause mortality (3.57% vs. 1.08%, p = 0.031), major adverse cardiovascular and cerebrovascular events (MACCE) (23.32% vs. 13.65%, p = 0.014), recurrent MR > 2+ (8.04% vs. 2.49%, p = 0.001) and NYHA III-IV (11.61% vs. 5.53%, p = 0.012) were more frequent in OHCM patients with MAC after myectomy. MAC was discovered to be an independent predictor of postoperative recurrent MR > 2+ after other risk factors were taken into account (HR 2.47, 95% CI 1.08-5.67, p = 0.0329). Moderate-to-severe MAC was an independent risk factor (HR 2.03, 95% CI 1.09-3.75, p = 0.0244) for long-term major adverse cardiovascular and cerebrovascular events (MACCE). CONCLUSION: MAC was detected in one-tenth of OHCM patients in preoperative CT scanning and is mainly associated with aging and atherosclerosis. OHCM patients with MAC had a worse prognosis and more recurrent mitral valve regurgitation than those without MAC after septal myectomy.

High-Burden Premature Atrial Contractions Predict New-Onset Atrial Fibrillation After Surgical Septal Myectomy.

Although increased premature atrial contractions (PACs) reportedly predict atrial fibrillation (AF) in both general and specific (e.g., patients with stroke) populations, early postoperative AF (POAF) risk in patients with increased PAC burden who require cardiac surgery remains unclear. We examined the correlation between different preoperative PAC burdens and POAF in patients with obstructive hypertrophic cardiomyopathy (OHCM) who underwent surgical treatment. We analyzed 304 consecutively admitted patients with OHCM without previous AF who underwent isolated septal myectomy between January 2015 and December 2018. All patients underwent preoperative 24-hour Holter electrocardiogram monitoring. PACs were present in 259 patients (85.20%) and absent in 45 patients (14.80%). According to the cut-off PAC number of 100 beats/24 hours, there were 211 patients (69.41%) with low-burden PACs and 48 patients (15.79%) with high-burden PACs. AF after septal myectomy occurred in 73 patients, which consisted of 3/45 in the non-PAC group (6.67%), 47/211 in the low-PAC-burden group (22.27%), and 23/48 in the high PAC burden group (47.92%). POAF incidence was higher in both low- and high-burden patients than in patients without PAC (p <0.01). Multivariate logistic regression analyses demonstrated that high-burden PACs (p = 0.02) and age (p <0.01) but not low-burden PACs (p = 0.22) independently predicted POAF in patients with OHCM. The area under the receiver operating characteristic curve for preoperative PACs was 0.72 (95% confidence interval 0.66 to 0.79, p <0.01, sensitivity: 68.49%, specificity: 69.26%). In conclusion, POAF incidence was significantly higher in patients with preoperative high-burden PACs and can predict POAF in patients with OHCM.

Atrial high-rate episode burden and stroke risks for patients with device-detected subclinical atrial fibrillation: A systematic review and meta-analysis.

BACKGROUND: Atrial high-rate episode (AHRE) and stroke are related; however, the magnitude of the correlations between different AHRE burdens and stroke remains unknown. We analysed studies that evaluated this relationship. METHODS: We searched for observational controlled studies that reported the associations of different AHRE burdens with stroke in populations with cardiac implantable electronic devices (CIEDs). The primary endpoint was stroke or thrombosis during follow-up. We performed subgroup analyses according to the classification criteria and research design of the included studies. RESULTS: Of the 5985 studies identified, 9 met the eligibility criteria and included 42,958 patients. Patients with low and high AHRE burdens had a 1.2-fold risk of stroke (no heterogeneity) and a 2.52-fold risk of stroke (moderate heterogeneity), respectively. After excluding studies analysing the atrial fibrillation history, no significant difference in progressive stroke risk was observed for patients with a low AHRE burden (without significant heterogeneity). An increased likelihood of stroke was observed for patients with a high AHRE burden (decreased heterogeneity). Four of the nine studies classified high and low AHRE burdens using the longest AHRE time. Five studies classified high and low AHRE burdens based on the median of the total AHRE time as the cutoff value. Low and high AHRE burdens were more closely related to stroke when classified by the total AHRE duration than when classified by the single longest AHRE duration. CONCLUSIONS: For populations with CIEDs without an atrial fibrillation history, a high AHRE burden was significantly associated with stroke.

Impact of Body Mass Index on Postoperative Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy Undergoing Septal Myectomy.

Background Obesity is an established cardiovascular risk factor in patients with hypertrophic cardiomyopathy. Postoperative atrial fibrillation (POAF) is one of the most common complications after surgery in patients with obstructive hypertrophic cardiomyopathy (OHCM). We aimed to determine the impact of body mass index (BMI) on the occurrence of POAF in patients with OHCM who underwent septal myectomy. Methods and Results In all, 712 OHCM patients without previous atrial fibrillation who underwent septal myectomy were identified. Patients were stratified into 3 groups based on BMI. Of these, 224 (31.5%) had normal weight (BMI<24 kg/m2), 339 (47.6%) were overweight (BMI, 24 to <28 kg/m2), and 149 (20.9%) were obese (BMI≥28 kg/m2). Overweight and obese patients had increased levels of left atrial diameter (P<0.001) and left ventricular end-diastolic diameter (P<0.001), compared with patients with normal weight. Among 184 patients (25.8%) developing POAF, 32 cases (14.3%) occurred in the normal weight group, 100 cases (29.5%) occurred in the overweight group, and 52 cases (34.9%) occurred in the obese group (P<0.001). Logistic regression analysis indicated that overweight (odds ratio [OR]: 2.161, 95% CI, 1.333-3.503; P=0.002) or obesity (OR, 2.803; 95% CI, 1.589-4.944; P<0.001), age (OR, 1.037; 95% CI, 1.018-1.057; P<0.001), and left atrial diameter (OR, 1.060; 95% CI, 1.027-1.095; P<0.001) were independently associated with the occurrence of POAF in patients with OHCM. Conclusions Overweight and obesity are strong predictors of POAF in patients with OHCM. Strategies aimed at lowering BMI may be a potential way to prevent POAF.

Left ventricular basal muscle bundle in hypertrophic cardiomyopathy: insights into the mechanism of left ventricular outflow tract obstruction.

AIMS: Many factors cause left ventricular outflow tract obstruction (LVOTO) in hypertrophic cardiomyopathy (HCM). Previous studies reported that left ventricular basal muscle bundle (BMB) may be associated with LVOTO. We aimed to evaluate the role of BMB in LVOTO by echocardiography. METHODS AND RESULTS: Two hundred fifty-six patients diagnosed with HCM were recruited. The morphologic characteristics of left ventricular outflow tract (LVOT) were analysed. BMB was detected in 178 (69.5%) patients by echocardiography. Patients were separated by a resting or provocative LVOT gradient ≥30 mmHg or not. Compared to patients without LVOTO, patients with LVOTO had a significantly thicker basal septum, elongated anterior mitral leaflet (AML), shorter distance between the AML-free margin and the septum or BMB (M-sept/bundle), larger angle between the plane of the mitral valvular orifice and the ascending aorta (MV-AO angle), and higher prevalence of BMB (P < 0.05). According to multivariate analysis, the independent predictors of LVOTO were the presence of BMB, a large basal septum thickness, a short M-sept/bundle, a large MV-AO angle, and a large AML [odds ratio (95% confidence interval): 5.207 (1.381-19.633), 1.386(1.141-1.683), 0.615(0.499-0.756), 1.113(1.054-1.176), and 1.343(1.076-1.677), respectively, P < 0.05]. Of the 256 included patients, 139 underwent surgical myectomy. The transthoracic echocardiography, compared with surgical specimen, showed: sensitivity 98.3%, specificity 82.3%, positive predictive value 97.6%, negative predictive value 87.5%, and accuracy 96.4% to detect BMB. CONCLUSIONS: BMB is common in HCM. BMB is a risk factor for LVOTO.

Clinical Efficacy and Safety of Cox-Maze IV Procedure for Atrial Fibrillation in Patients With Hypertrophic Obstructive Cardiomyopathy.

Objective: Atrial fibrillation is the most prevalent persistent arrhythmia in patients with hypertrophic obstructive cardiomyopathy. Comparative analyses of the safety and effectiveness of septal myectomy with and without surgical ablation are limited. This study aimed to compare the outcomes of septal myectomy with and without the Cox-maze IV procedure in patients with hypertrophic obstructive cardiomyopathy and atrial fibrillation. Methods: Ninety-four patients with hypertrophic obstructive cardiomyopathy and atrial fibrillation who underwent septal myectomy were analyzed, we divided it into concomitant Cox maze surgery (Cox-maze group) and no concomitant Cox maze operation (no Cox-maze group). Freedom from atrial fibrillation recurrence and all-cause mortality after surgery were assessed. Results: Freedom from all-cause mortality after septal myectomy at 1, 3, and 5 years was 98.5 ± 1.5% each in the Cox-maze group and 90.8 ± 6.3%, 85.1 ± 8.1%, and 85.1 ± 8.1%, respectively, in the no Cox-maze group. Patients in the no Cox-maze group had lower survival, freedom from atrial fibrillation recurrence off antiarrhythmic drugs, and arrhythmia control rate (including patients with successful antiarrhythmic drug conversion) than those in the Cox-maze group (P = 0.046, P = 0.040, and P = 0.012, respectively). Patients who underwent the Cox-maze IV procedure had lower atrial fibrillation recurrence rate than those who did not (hazard ratio, 0.141; 95% confidence interval, 0.042-0.479; P = 0.002). Post-operative increases in left atrial diameters (hazard ratio, 1.099; 95% confidence interval, 1.024-1.179; P = 0.009) were associated with atrial fibrillation recurrence. Conclusions: The Cox-maze IV procedure combined with septal myectomy improved mid-term survival and reduced mid-term atrial fibrillation recurrence in patients with hypertrophic obstructive cardiomyopathy and atrial fibrillation. The concomitant Cox-maze IV procedure was associated with a lower atrial fibrillation recurrence in patients with surgical hypertrophic obstructive cardiomyopathy and atrial fibrillation.

Myocardial bridging of the left anterior descending coronary artery as a risk factor for atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy: a matched case-control study.

BACKGROUND: Myocardial bridging (MB) is associated with various forms of arrhythmia. However, whether MB is a risk factor for atrial fibrillation (AF) in patients with hypertrophic obstructive cardiomyopathy (HOCM) remains unknown. This study aimed to identify the relationship between myocardial bridging of the left anterior descending coronary artery (MB-LAD) and AF in patients with HOCM. METHODS: We reviewed the medical records of 1925 patients diagnosed with HOCM at Fuwai Hospital from January 2012 to March 2019. Patients with coronary artery disease, a history of heart surgery, and those who had not been subjected to angiography were excluded. Finally, 105 patients with AF were included in this study. The control group was matched in a ratio of 3:1 based on age and gender. RESULTS: Forty-three patients were diagnosed with MB-LAD in this study. The presence of MB was significantly higher in patients with AF than in those without AF (19.0% vs. 7.3%; p = 0.001), although MB compression and MB length did not differ between the two groups. In conditional multivariate logistic analysis, MB (odds ratio [OR] 2.33; 95% confidence interval [CI] 1.08-5.01; p = 0.03), pulmonary arterial hypertension (OR 2.63; 95% CI 1.26-5.47; p = 0.01), hyperlipidemia (OR 1.83; 95% CI 1.12-3.00; p = 0.016), left atrial diameter (OR 1.09; 95% CI 1.05-1.13; p < 0.001), and interventricular septal thickness (OR 1.06; 95% CI 1.003-1.12; p = 0.037) were independent risk factors for AF in patients with HOCM. CONCLUSIONS: The presence of MB is an independent risk factor for AF in patients with HOCM. The potential mechanistic link between MB and the development of AF warrants further investigation.

Risk Factors of Pulmonary Arterial Hypertension and Its Relationship With Atrial Fibrillation in Patients With Obstructive Hypertrophic Cardiomyopathy.

Background: Pulmonary arterial hypertension (PH) is a common complication in patients with obstructive hypertrophic cardiomyopathy (OHCM). The risk factor of PH in patients with OHCM has not been fully elucidated, and even atrial fibrillation (AF) was considered a risk factor of PH. Thus, our study aimed to investigate risk factors of PH and the relationship between PH and AF in patients with OHCM. Methods: We retrospectively enrolled 483 consecutive patients diagnosed with OHCM at Fuwai Hospital (Beijing, China) from January 2015 to December 2017. Clinical and echocardiographic parameters were compared between patients with and without PH. Results: Eighty-two (17.0%) patients were diagnosed with PH in this study. Compared to patients without PH, those with PH were significantly older, had a lower body mass index (BMI), were more likely to be female and more symptomatic [New York Heart Association Class 3 or 4 symptoms], and had a higher AF prevalence. A multivariate analysis indicated that AF was an independent risk factor of PH (odds ratio [OR] 2.31, 95% confidence interval [CI] 1.03-5.20, p = 0.042). Moreover, PH was independently associated with a higher AF incidence after adjusting for age and left atrial diameter (OR 2.24, 95% CI 1.07-4.72, p = 0.034). Conclusion: AF was independently associated with PH in patients with OHCM. Further, PH was significantly associated with an increased risk of AF, which suggested that AF could aggravate PH and that PH may promote AF processes, forming a vicious circle.

The preoperative glomerular filtration rate predicts new-onset postoperative atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy who undergo isolated septal myectomy.

BACKGROUND: Few studies have focused on new-onset postoperative atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy who have undergone septal myectomy. Therefore, we investigated the incidence and prognosis effects of postoperative atrial fibrillation following septal myectomy in patients with hypertensive obstructive cardiomyopathy. Additionally, we investigated the relationship of estimated glomerular filtration rate and postoperative atrial fibrillation. METHODS: Data from 300 patients with hypertrophic obstructive cardiomyopathy who underwent isolated surgical septal myectomy were collected from January 2012 to March 2018. RESULTS: The overall incidence of postoperative atrial fibrillation during hospitalization was 22.67% (68 of 300 patients). Patients with postoperative atrial fibrillation were older (P<0.001), had lower preoperative estimated glomerular filtration rate (P<0.001), and a larger preoperative left atrial diameter (P=0.038) compared to patients without. The preoperative estimated glomerular filtration rate predicted postoperative atrial fibrillation with sensitivity and specificity of 0.824 and 0.578 (P<0.001), respectively. Multivariate regression analyses showed that age [odds ratio (OR) =1.090, 95% confidence interval (CI): 1.034-1.110], an New York Heart Association functional class ≥ III (OR =2.985, 95% CI: 1.349-6.604), hypertension (OR =2.212, 95% CI: 1.062-4.608), a history of syncope (OR =3.890, 95% CI: 1.741-8.692), and the preoperative estimated glomerular filtration rate (OR =0.981, 95% CI: 0.965-0.996) were independent risk factors associated in the development of postoperative atrial fibrillation. Survival analysis showed that the incidence of long-term cardiovascular events was higher in the patients with postoperative atrial fibrillation than that in the patients without the condition (P<0.001). CONCLUSIONS: The preoperative estimated glomerular filtration rate was a moderate predictor of postoperative atrial fibrillation after septal myectomy. Postoperative atrial fibrillation affected the early recovery and the long-term prognoses of patients with hypertrophic obstructive cardiomyopathy who underwent septal myectomy.

Mid-ventricular obstruction is associated with non-sustained ventricular tachycardia in patients with hypertrophic obstructive cardiomyopathy.

BACKGROUND: Mid-ventricular obstruction (MVO) is a rare subtype of hypertrophic cardiomyopathy (HCM) but it is associated with ventricular arrhythmia. The relationship between MVO and non-sustained ventricular tachycardia (NSVT) in HCM patients is unknown. HYPOTHESIS: The severity of MVO increases the incidence of NSVT in patients with hypertrophic obstructive cardiomyopathy (HOCM). METHODS: Five hundred and seventy-two consecutive patients diagnosed with HOCM in Fuwai Hospital between January 2015 and December 2017 were enrolled in this study. Holter electrocardiographic and clinical parameters were compared between HOCM patients with and without MVO. RESULTS: Seventy-six (13.3%) of 572 patients were diagnosed with MVO. Compared to patients without MVO, those with MVO were much younger, and had a higher incidence of syncope, greater left ventricular (LV) posterior wall thickness, a higher percentage of LV late gadolinium enhancement, and higher prevalence of NSVT. Furthermore, the prevalence of NSVT increased with the severity of MVO (without, mild, moderate or severe: 11.1%, 18.2%, 25.6%, respectively, p for trend < .01). Similarly, the prevalence of NSVT differed among patients with isolated LV outflow tract (LVOTO), both MVO and LVOTO, and isolated MVO (11.1%, 21.3%, 26.6%, respectively, p for trend = .018). In addition to age, diabetes, left atrial diameter, and maximal wall thickness, multivariate analysis revealed the presence of MVO as an independent risk factor for NSVT (Odds ratio 2.69; 95% confidence interval 1.41 to 5.13, p = .003). CONCLUSIONS: The presence and severity of MVO was associated with higher incidence of NSVT in HOCM patients.

Prevalence and characteristics of intramural coronary artery in hypertrophic obstructive cardiomyopathy: a coronary computed tomography and invasive angiography study.

BACKGROUND: The prevalence and morphologic characteristics of intramural coronary artery (ICA) in patients with hypertrophic obstructive cardiomyopathy (HOCM) have yet to be fully illuminated. Our study aimed to investigate the prevalence and morphologic characteristics of ICA in patients with HOCM using coronary computed tomography (CT) angiography and invasive coronary angiography. METHODS: Patients with a diagnosis of HOCM who were admitted for selective myectomy in Fuwai Hospital were prospectively enrolled between September 2015 and June 2019. Both preoperative coronary CT and invasive angiography were scheduled for all participants. RESULTS: Coronary CT angiography detected ICA in 106 (23.3%) out of 455 patients. Dynamic compression of coronary arteries was observed in 87 patients (19.1%) by invasive coronary angiography. We found ICA covered with complete myocardial encasement in 98 patients (92.5%), with deep myocardial bridging (MB) observed most frequently (P=0.005). All patients with dynamic compression of coronary arteries had ICA. Dynamic luminal reduction ≥50% was present in 77 (16.9%) of the study participants. Pearson's correlation analysis revealed that the length and degree of dynamic compression were significantly related with MB length and depth (Pearson's correlation r=0.241, 0.581, 0.316, and 0.209; P=0.014, <0.001, 0.002, and 0.032, respectively). CONCLUSIONS: Patients with HOCM commonly present with ICA and it can be visualized well by coronary CT angiography. Deep or extensive MB is more likely to produce coronary artery dynamic compression. Preoperative identification of this congenital coronary artery variant may be helpful for surgical planning.

Preoperative Statin Use Is Associated With Less Postoperative Atrial Fibrillation After Myectomy in Patients With Hypertrophic Obstructive Cardiomyopathy.

The present study aims to investigate whether preoperative statin use is associated with less postoperative atrial fibrillation occurrence after septal myectomy in patients with hypertrophic obstructive cardiomyopathy (HOCM). Clinical data of consecutive patients with HOCM who underwent septal myectomy between February 2009 and May 2019 at our institution was retrospectively reviewed. The cohort was divided into 2 groups according to the status of preoperative statin use (statin group vs no statin group). Logistic regression was used to explore associations of clinical variables with postoperative atrial fibrillation occurrence. A total of 1307 patients with HOCM underdoing septal myectomy were included in the present study, with 109 patients in the statin group and 1198 in the no statin group. Among 322 patients (24.6%) developing postoperative atrial fibrillation, 21 cases (19.3%) occurred in the statin group, while 301 cases (25.1%) were in the no statin group (P = 0.202). After propensity score matching with confounding variables at baseline, 91 paired patients were included in the matched cohort. Postoperative atrial fibrillation developed in 17 (18.7%) and 38 (41.8%) in the statin and no statin groups, respectively (P = 0.001). Preoperative statin use was associated with less postoperative atrial fibrillation occurrence (odds ratio 0.220, 95% confidence interval 0.083-0.588, P<0.003). The present study suggested that preoperative statin use was associated with less postoperative atrial fibrillation occurrence after septal myectomy in patients with HOCM. This finding may provide clues for subsequent prospective study to investigate this clinical issue.

Childhood Hypertrophic Obstructive Cardiomyopathy and Its Relevant Surgical Outcome.

BACKGROUND: Contemporary experiences regarding childhood hypertrophic obstructive cardiomyopathy are limited. This study aimed to describe the clinical presentation of childhood hypertrophic obstructive cardiomyopathy and its relevant surgical outcome. METHODS: In all, 117 consecutive children with hypertrophic obstructive cardiomyopathy aged 0.6 to 17.5 years who underwent septal myectomy at our institution between February 2009 and December 2018 were included. Medical records and other patient-related data were reviewed. RESULTS: In the present study, the anatomic and physiologic characteristics of childhood hypertrophic obstructive cardiomyopathy were highly heterogeneous, with simultaneous right ventricular outflow tract obstruction in 22 patients (18.8%), coronary myocardial bridging in 25 patients (21.4%), and intraventricular anatomic abnormalities in 61 patients (52.1%). The mean peak left or right ventricular outflow tract gradient, interventricular septal thickness, and degree of mitral regurgitation significantly decreased after surgery. One early death was noted in the study. During follow-up, three sudden cardiac deaths were noted. The overall survival rates at follow-up were 100% at 1 year and 96.5% at 3 years. The overall survival rates free from reoperation were 99.1% at 1 year and 98.0% at 3 years. CONCLUSIONS: In our cohort of children with hypertrophic obstructive cardiomyopathy undergoing septal myectomy, biventricular obstruction, myocardial bridging, and intraventricular anatomic abnormalities are frequent phenotypic components. Despite the complexity of childhood hypertrophic obstructive cardiomyopathy, surgical treatment results in a favorable outcome in carefully selected patients.