Predicting complete heart block after alcohol septal ablation for hypertrophic cardiomyopathy using a risk stratification model and clinical tool.

BACKGROUND: Alcohol septal ablation (ASA) is a proven method of septal reduction for patients with drug refractory, symptomatic hypertrophic obstructive cardiomyopathy (HOCM). This procedure is associated with a 6.5-11% risk of complete heart block (CHB). OBJECTIVE: The aim of this study is to determine factors that predict CHB and to develop a clinical tool for risk stratification of patients. METHODS: Patients were enrolled into an ongoing ASA study. A total of 636 patient procedures were included, 527 of whom were used in the development of the prediction tool, and 109 of whom were used for independent validation. Multivariate analysis was performed with odds ratios used to develop the clinical prediction tool. This was then internally and externally validated. RESULTS: Of the 527 in the prediction cohort, 46 developed CHB. The predictors of CHB were age ≥50 years, pre-ASA left bundle branch block (LBBB), transient procedural high-grade block, post-ASA PR prolongation ≥68 ms, and new bifascicular block. An 11-point clinical prediction tool was developed to classify these factors. Internal validation using a receiver operating characteristic curve revealed an area under the curve of 0.88 for the clinical prediction tool. External validation using 109 contemporary patients revealed a 98% negative predictive value, 24% positive predictive value, 75% sensitivity, and 81% specificity in high-risk patients. CONCLUSION: Among patients undergoing ASA, the risk of CHB can be predicted with easily obtained clinical and electrocardiographic factors. This clinical prediction tool allows identification of high-risk patients who may benefit from additional monitoring and therapy.

Alcohol septal ablation for obstructive hypertrophic cardiomyopathy: outcomes in young, middle-aged, and elderly patients.

OBJECTIVES: We compared the efficacy and safety of alcohol septal ablation (ASA) for obstructive hypertrophic cardiomyopathy (HCM) in young, middle-aged, and elderly patients. BACKGROUND: Intersociety guidelines suggest based on limited evidence that young patients with medically refractory symptoms of obstructive HCM should undergo surgical myectomy while elderly patients may be more appropriate for ASA. METHODS: Data for 360 patients undergoing 389 ASAs were prospectively collected and retrospectively analyzed according to age. RESULTS: Young (<45 years), middle-aged (45-64 years), and elderly (≥65 years) patients comprised 28, 40, and 32% of the study population, respectively. Young patients had thicker left ventricular septal walls at baseline, and elderly patients had more comorbidity and dyspnea. Resting, mean left ventricular outflow tract gradients (LVOTGs) were similar across the age groups at baseline (62, 66, and 68 mm Hg, respectively; P = NS for all comparisons). LVOTGs and dyspnea were significantly and similarly improved in all age groups immediately after ASA and through 12 months of follow-up (P < 0.001 for before and after comparisons; P = NS for intergroup comparisons). Complication rates were similar for young and middle-aged patients but higher for elderly patients (9.1 and 6.3% vs. 20.8%, respectively; P ≤ 0.016 for elderly vs. others). Mortality rates for young and middle-aged patients were lower than for elderly patients, but the differences were not statistically significant. CONCLUSIONS: Patients undergoing ASA had significant and similar improvements in LVOTGs and symptoms regardless of age. Procedural complications were increased in elderly patients, who had numerically but not statistically significantly higher mortality rates.

GuideLiner Balloon Assisted Tracking for deep cathether intubation to address challenging distal coronary lesions.

As the medical treatment and survivability of coronary artery disease improve, patients requiring catheter-based coronary intervention present with increasingly challenging coronary anatomy. Navigating complicated coronary anatomy requires a diverse armamentarium of techniques to reach distal target lesions. Here, we discuss a case in which we used GuideLiner Balloon Assisted Tracking, a technique formerly used to achieve difficult radial access, to facilitate delivery of a drug-eluting stent to a challenging coronary target.

Coronary CT angiography versus conventional cardiac angiography for therapeutic decision making in patients with high likelihood of coronary artery disease.

PURPOSE: To assess the efficacy of coronary computed tomographic (CT) angiography for therapeutic decision making in patients with high likelihood of coronary artery disease (CAD)-specifically the ability of coronary CT angiography to help differentiate patients without and patients with a need for revascularization and determine the appropriate revascularization procedure. MATERIALS AND METHODS: The study protocol was approved by institutional review board, with written informed consent from all patients. The study was conducted in compliance with HIPAA. One hundred eighty-five consecutive symptomatic patients (121 men; mean age, 59.4 years±9.7) with a positive single photon emission computed tomography (SPECT) myocardial perfusion study underwent coronary CT angiography and conventional cardiac angiography (hereafter, cardiac catheterization). The management strategy (conservative treatment vs revascularization) and revascularization procedure (percutaneous coronary intervention [PCI] vs coronary artery bypass graft surgery [CABG]) were prospectively selected on the basis of a combination of coronary CT angiography and SPECT. In addition, the authors calculated the accuracy, sensitivity, specificity, and negative and positive predictive values of coronary CT angiography in the detection of obstructive CAD and the selection of a revascularization strategy. Cardiac catheterization was used as the standard of reference. RESULTS: Of the 185 patients, 113 (61%) did not undergo revascularization and 42 (23%) were free of CAD. In 178 patients (96%), the same therapeutic strategy (conservative treatment vs revascularization) was chosen on the basis of coronary CT angiography and catheterization. All patients in need of revascularization were identified with coronary CT angiography. When revascularization was indicated, the same procedure (PCI vs CABG) was chosen in 66 of 72 patients (92%). CONCLUSION: In patients with high likelihood of CAD, the performance of coronary CT angiography in the differentiation of patients without and patients with a need for revascularization and the selection of a revascularization strategy was similar to that of cardiac catheterization; accordingly, coronary CT angiography has the potential to limit the number of patients without obstructive CAD who undergo cardiac catheterization and to inform decision making regarding revascularization.

Improved Outcomes With Transradial Approach in Alcohol Septal Ablation.

BACKGROUND: Transradial cardiac catheterization is equally effective but has fewer vascular complications than transfemoral catheterization. There is a paucity of data on biradial approach for alcohol septal ablation (ASA). This study seeks to study the differences in procedural outcomes between the transradial vs traditional transfemoral approach in ASA. METHODS: A total of 274 consecutive patients who underwent ASA were retrospectively assigned to the study subgroups (137 transradial, 137 femoral). Procedural success, reduction in left ventricular outflow tract gradient (LVOTG), contrast volume, fluoroscopy time, and complications were compared between the 2 groups. RESULTS: There were no differences in reduction of resting LVOTG (91% vs 92%; P=.50), provoked LVOTG (80% vs 82%; P=.47) post procedure between transradial vs transfemoral subgroups. Iodinated contrast volume was significantly lower in the transradial group (98 mL vs 111 mL; P=.04), whereas fluoroscopy time was higher in the transradial group (17.42 minutes vs 13.00 minutes; P<.001). The incidence of complications was lower in the transradial group (0.13 vs 0.23; P=.04). CONCLUSIONS: ASA via transradial approach is equally effective and associated with significantly less contrast use and fewer complications as compared with the traditional transfemoral approach.

Defibrillation thresholds in hypertrophic cardiomyopathy.

BACKGROUND: Defibrillation threshold (DFT) testing is performed in part to ensure an adequate safety margin for the termination of spontaneous ventricular arrhythmias. Left ventricular mass is a predictor of high DFTs, so patients with hypertrophic cardiomyopathy (HCM) are often considered to be at risk for increased defibrillation energy requirements. However, there are little prospective data addressing this issue. OBJECTIVE: To assess DFTs in patients with HCM and evaluate the clinical predictors of elevated DFTs. METHODS: Eighty-nine consecutive patients with HCM and 600 control patients with ischemic or nonischemic cardiomyopathy underwent a uniform modified step-down DFT testing protocol. DFT was compared between the control and HCM populations. Predictors of elevated DFT were evaluated in the HCM group. RESULTS: There was no difference in DFT between HCM and control groups (10.4 ± 5.8 J vs 11.2 ± 5.6 J, respectively). Among patients with HCM, clinical parameters such as left ventricular ejection fraction, interventricular septal thickness, left ventricular mass, and QRS duration were not predictive of an elevated DFT. Only 3 patients (3.4%) with HCM had a DFT >20 J. CONCLUSION: Patients with HCM do not have elevated DFTs as compared to more typical populations undergoing implantable cardioverter-defibrillator implant; high-energy devices or complex lead systems are not needed routinely in this population.

Transaxillary Intra-Aortic Balloon Pump Migration Minimized With a Long Introducer Sheath.

Intra-aortic balloon pump (IABP) has been used more recently as a bridge to cardiac transplantation in hospitalized patients. Femoral IABP limits mobility and rehabilitation; thus, transaxillary approach has been described. However, a transaxillary IABP may migrate, causing significant vascular injury, potential death, or disqualification from transplantation. We describe a case of a 67-year-old male with transaxillary IABP inserted to allow for pre-transplant physical rehabilitation. Due to the unfolded nature of his aorta, the IABP coiled onto itself and migrated several times. We employed a novel technique to mitigate IABP migration using a long 25-cm introducer sheath.

Long-Term Survival After Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy: A 16-Year Experience.

BACKGROUND: Alcohol septal ablation (ASA) is an accepted treatment for medically refractory hypertrophic obstructive cardiomyopathy (HOCM). The procedural and medium-term outcomes have been reassuring. The iatrogenic targeted septal infarction has raised theoretical concerns about risk of arrhythmia and long-term survival. In this study, we describe the long-term survival in a large cohort of patients from a single referral center and the iterative improvement in procedural technique since its inception. METHODS: This cohort includes 580 consecutive patients who underwent 664 ASA procedures between the years 1999 and 2015. Procedural details and outcomes are described. Long-term survival is compared with expected survival of demographically similar controls. RESULTS: Fifty-four percent were women and 85% were Caucasian. At the time of ablation, mean age was 57 ± 15 years, septal thickness was 2.1 ± 0.5 cm, and left ventricular outflow tract (LVOT) gradient was 72 ± 40 mm Hg at rest and 102 ± 58 mm Hg with Valsalva provocation. Mean follow-up was 8.0 ± 4.3 years. LVOT gradient reduction >50% was achieved in 94% of patients with reduction in New York Heart Association functional class scores and increase in exercise treadmill duration. Procedural mortality was 0.9%. Over the 16-year period, survival estimates at 1, 5, 10, and 15 years were 98%, 92%, 84%, and 81%, respectively, which are comparable to demographically similar controls. The standardized mortality ratio was 0.84 (95% confidence interval, 0.66-1.06); P=.09. CONCLUSIONS: ASA appears to be a safe and effective treatment for symptomatic HOCM refractory to medical therapy with long-term survival comparable to a demographically similar United States population.

Call a Spade a Spade: Missed Diagnosis of Apical Hypertrophic Cardiomyopathy.

Apical hypertrophic cardiomyopathy is a variant of hypertrophic cardiomyopathy characterized by apical hypertrophy, deep T-wave inversions in precordial electrocardiogram (EKG) leads, and a ventriculogram shaped like the "Ace of Spades." Patients are often asymptomatic but sometimes present with atypical chest pain, angina, or atrial fibrillation. The deep T-wave inversions on EKG often mimic acute coronary syndrome. Coronary angiogram in these patients is unrevealing, but the characteristic left ventriculogram establishes this diagnosis. The deep T-wave inversions can appear suddenly or deepen over years, making the diagnosis difficult to establish early in the disease. Transthoracic echocardiogram may miss the hypertrophied apex, but echo contrast imaging or cardiac magnetic resonance imaging can reliably confirm the diagnosis and detect apical aneurysms. We present a case of apical hypertrophic cardiomyopathy which was not evident despite many admissions, EKGs, cardiac catheterizations and echocardiograms until the diagnosis was confirmed with left ventriculogram and cardiac magnetic resonance imaging 20 years after initial presentation.

Novel Technique of Surgical Management of Scimitar Syndrome.

Scimitar syndrome is a rare congenital abnormality resulting from right-sided pulmonary venous return to the inferior vena cava rather than to the left atrium. It is usually detected in early childhood with symptoms of recurrent chest infection and finding of pulmonary hypertension due to left to right shunt. We report a case of a 40-year-old woman with scimitar syndrome discovered on chest X-ray during evaluation of recurrent pneumonia. Surgical correction was achieved with a novel technique of using a synthetic graft connecting the scimitar vein across the right atrium to the left atrium along with ligation of the scimitar vein connection to the inferior vena cava. The patient continues to do well 10 years after surgery, and the shunt graft shows good flow on echocardiogram. We present her clinical and imaging data and details of the surgical technique along with a brief review of surgical literature.

Relation of Lymphangiogenic Factor Vascular Endothelial Growth Factor-D to Elevated Pulmonary Artery Wedge Pressure.

Lymphatic flow is augmented in states of chronic heart failure (cHF). However, the biological mechanism driving increased lymphatic flow capacity (lymphangiogenesis) in cHF is unknown. Recent studies have indicated that vascular endothelial growth factors (VEGF-A, -C, and -D) are involved in lymphangiogenesis. This study examined the association between VEGF-A, -C, and -D levels, invasively measured hemodynamics, and heart failure symptoms. Subjects who underwent clinically indicated right heart catheterization at Medical University of South Carolina between 12/2016 and 7/2018 were eligible for inclusion. These subjects underwent clinical assessment of cHF severity (including 6MWT and KCCQ), hemodynamic assessment with right heart catheterization, laboratory studies including B-type natriuretic peptide, and concomitant measurement of VEGF-A, -C, and -D. Fifty-six patients were included for analysis. Subjects with elevated pulmonary artery wedge pressure (PAWP) had significantly higher VEGF-D levels (263 ± 415 pg/ml vs 65 ± 101 pg/ml; p = 0.02). PAWP was not associated with VEGF-A or VEGF-C levels. When stratified by VEGF-D, subjects with elevated VEGF-D had clinical and hemodynamic characteristics associated with worse HF severity (lower ejection fraction, higher b-type natriuretic peptide, higher PAWP, lower cardiac output), but were not more symptomatic by Kansas City Cardiomyopathy Questionnaire scores and had similar 6-minute walk test distance compared with subjects with lower VEGF-D. Subjects with an elevated VEGF-D were more likely to have a diagnosis of heart failure for >3 years. In conclusion, VEGF-D is associated with elevated PAWP in cHF, and elevated VEGF-D may mitigate cHF symptoms.

Percutaneous Coronary Intervention in an 8-Month-Old Infant for Ostial Stenosis of a Reimplanted Left Main Coronary Artery.

Percutaneous coronary intervention (PCI) is a routine procedure undertaken in adult patients. In children, the procedure remains rare and challenging due to a multitude of factors including but not limited to complex congenital heart disease anatomy, catheter and stent to patient size mismatch, and lack of data for post-PCI antiplatelet therapy. We present a case of PCI in an 8-month-old infant with anomalous left coronary artery from pulmonary artery (ALCAPA) who developed severe ostial kinking of the left main coronary artery (LMCA) after surgical reimplantation of the anomalous coronary. A 3.5 × 8 mm Vision bare metal stent was successfully placed into the LMCA and postdilated with excellent results. Follow-up echocardiography at 6 months post-PCI demonstrated a patent stent with normal Doppler flow signals. Despite initial success, the infant developed severe heart failure and was listed for orthotopic heart transplantation at age 20 months, one year after PCI. Given the paucity of published data regarding PCI and outcomes in infants with ALCAPA after surgical reimplantation, we describe our case and present a review of the available literature.

Diagnostic yield and accuracy of coronary CT angiography after abnormal nuclear myocardial perfusion imaging.

We aimed to determine the diagnostic yield and accuracy of coronary CT angiography (CCTA) in patients referred for invasive coronary angiography (ICA) based on clinical concern for coronary artery disease (CAD) and an abnormal nuclear stress myocardial perfusion imaging (MPI) study. We enrolled 100 patients (84 male, mean age 59.6 ± 8.9 years) with an abnormal MPI study and subsequent referral for ICA. Each patient underwent CCTA prior to ICA. We analyzed the prevalence of potentially obstructive CAD (≥50% stenosis) on CCTA and calculated the diagnostic accuracy of ≥50% stenosis on CCTA for the detection of clinically significant CAD on ICA (defined as any ≥70% stenosis or ≥50% left main stenosis). On CCTA, 54 patients had at least one ≥50% stenosis. With ICA, 45 patients demonstrated clinically significant CAD. A positive CCTA had 100% sensitivity and 84% specificity with a 100% negative predictive value and 83% positive predictive value for clinically significant CAD on a per patient basis in MPI positive symptomatic patients. In conclusion, almost half (48%) of patients with suspected CAD and an abnormal MPI study demonstrate no obstructive CAD on CCTA.

A prospective follow-up of alcohol septal ablation for symptomatic hypertrophic obstructive cardiomyopathy--the Baylor experience (1996-2002).

BACKGROUND: There is a paucity of data on the long-term outcome of alcohol septal ablation (ASA) for symptomatic hypertrophic obstructive cardiomyopathy (HOCM). HYPOTHESIS: The study was undertaken to evaluate the longer-term outcome of ASA therapy for symptomatic HOCM. METHODS: In all, 137 patients were enrolled consecutively (1996-1999) and 130 (95%) (74 men, 56 women, aged 51 +/- 17 years) underwent ASA and had serial prospective follow-up for up to 5 years (mean follow-up 3.6 +/- 1.4 years). Evaluation included angina (Canadian Cardiovascular Society [CCS] score), dyspnea (New York Heart Association [NYHA] class), duration of exercise on treadmill, and echocardiographic indices. RESULTS: Ethanol (3.5 +/- 1.5 cc), injected into 1.5 +/- 0.6 arteries, induced a mean peak plasma creatine kinase (CK) of 1676 +/- 944 units. Complications of procedures included death 1.5% (2/130), heart block requiring permanent pacemaker 13% (17/130), and coronary dissection 4.4% (6/130). Baseline versus last follow-up visit: NYHA class decreased from 3.0 +/- 0.4 to 1.2 +/- 0.6 (p < 0.01); CCS angina score from 2.0 +/- 0.8 to 0.08 +/- 0.4 (p < 0.01); and duration of exercise increased from 322 +/- 207 to 443 +/- 200 s (p < 0.01). Resting left ventricular outflow tract gradient at baseline versus last follow-up visit showed a decrease from 74 +/- 30 to 4 +/- 13 (p < 0.01), and the dobutamine-provoked gradient of 88 +/- 29 decreased to 21 +/- 21 (p < 0.01) mmHg. All-cause mortality over the duration of follow-up was 7.7% (10) giving an annual rate of 2.1%, and cardiac mortality was 2.3% (3) reflecting an annual rate of 0.6%. CONCLUSIONS: Alcohol septal ablation decreased symptoms and improved exercise performance, indicating that it is an effective procedure for symptomatic HOCM.

Peak early diastolic velocity rather than pressure half-time is the best index of mechanical prosthetic mitral valve function.

Reliable screening of mechanical prosthetic mitral valve (PMV) dysfunction by transthoracic echocardiography (TTE) is mandatory because transesophageal echocardiography (TEE) cannot be routinely used. However, acoustic shadowing seriously hampers detection of PMV dysfunction with TTE, particularly regurgitation. To identify TTE indexes that can detect PMV dysfunction (regurgitation or obstruction), 134 patients (age 60 +/- 12 years, 64 men) with PMV who underwent TTE and TEE within 3 +/- 5 days were assessed. There were 73 normal and 61 dysfunctional valves (40 regurgitant, 21 obstructive). By multivariate analysis, peak E velocity was the best predictor of a dysfunctional valve. Both peak E velocity (E > or =1.9 m/s; sensitivity 92%, specificity 78%) and the ratio of velocity-time integrals of flow through the prosthesis to that of the left ventricular outflow (VTI(pmv/)VTI(lvo) > or =2.2; sensitivity 91%, specificity 74%) were successful in detecting PMV dysfunction. Although pressure half-time (PHT) readily identified PMV obstruction, it did not detect regurgitation. Logistic models including peak E velocity and VTI(pmv)/VTI(lvo) or PHT were equally successful in detecting PMV dysfunction. However, all 3 variables were needed to best distinguish among normal, obstructed, and regurgitant valves. A peak E velocity > or =1.9 m/s and VTI(pmv)/VTI(lvo) ratio > or =2.2 predicted valve regurgitation in 83% of valves when PHT was < 130 ms, and valve stenosis in 95% when PHT was >130 ms. Importantly, a peak E velocity < 1.9 m/s, VTI(pmv)/VTI(lvo) ratio < 2.2, and a PHT < 130 ms had a predictive accuracy for a normal valve of 98%. Thus, TTE Doppler indexes can be used as screening parameters of PMV dysfunction and help select patients for further diagnostic evaluation with TEE.

Diagnostic accuracy and cost-effectiveness of contrast echocardiography on evaluation of cardiac function in technically very difficult patients in the intensive care unit.

Echocardiographic assessment of cardiac function can be quite difficult in the intensive care unit and may require transesophageal echocardiography (TEE). We therefore compared harmonic imaging alone or in combination with contrast to TEE in 32 consecutive patients in the intensive care units who were considered technically very difficult (> or =50% of the 16 segments not visualized from any view). Excellent or adequate endocardial visualization was achieved in 13% of segments with fundamental imaging, 34% with harmonic imaging, and 87% with contrast (p < 0.0001); the latter success rate was similar to TEE (87% vs 90%; p = NS). When TEE was used as the standard, agreement in exact interpretation of wall motion increased from 48% for fundamental imaging to 58% with harmonic imaging, and reached 70% with contrast (p <0.0001). Contrast had the best sensitivity (89%) for detecting wall motion abnormalities. Estimation of ejection fraction was possible in 31% with fundamental imaging, 50% with harmonic imaging, and in 97% with contrast. Ejection fraction quantitated by contrast enhancement correlated best with TEE (r = 0.91). Cost-effectiveness analysis revealed that contrast echo was cost-effective compared with TEE in determining regional and global ventricular function, with a cost saving of 3% and 17%, respectively. Thus, contrast echocardiography provides an accurate, safe, and cost-effective alternative to TEE for evaluating ventricular function in technically very difficult studies.

Left ventricular end-diastolic pressure affects measurement of fractional flow reserve.

BACKGROUND: Fractional flow reserve (FFR), the hyperemic ratio of distal (Pd) to proximal (Pa) coronary pressure, is used to identify the need for coronary revascularization. Changes in left ventricular end-diastolic pressure (LVEDP) might affect measurements of FFR. METHODS AND MATERIALS: LVEDP was recorded simultaneously with Pd and Pa during conventional FFR measurement as well as during additional infusion of nitroprusside. The relationship between LVEDP, Pa, and FFR was assessed using linear mixed models. RESULTS: Prospectively collected data for 528 cardiac cycles from 20 coronary arteries in 17 patients were analyzed. Baseline median Pa, Pd, FFR, and LVEDP were 73 mmHg, 49 mmHg, 0.69, and 18 mmHg, respectively. FFR<0.80 was present in 14 arteries (70%). With nitroprusside median Pa, Pd, FFR, and LVEDP were 61 mmHg, 42 mmHg, 0.68, and 12 mmHg, respectively. In a multivariable model for the entire population LVEDP was positively associated with FFR such that FFR increased by 0.008 for every 1-mmHg increase in LVEDP (beta=0.008; P<0.001), an association that was greater in obstructed arteries with FFR<0.80 (beta=0.01; P<0.001). Pa did not directly affect FFR in the multivariable model, but an interaction between LVEDP and Pa determined that LVEDP's effect on FFR is greater at lower Pa. CONCLUSIONS: LVEDP was positively associated with FFR. The association was greater in obstructive disease (FFR<0.80) and at lower Pa. These findings have implications for the use of FFR to guide revascularization in patients with heart failure. SUMMARY FOR ANNOTATED TABLE OF CONTENTS: The impact of left ventricular diastolic pressure on measurement of fractional flow reserve (FFR) is not well described. We present a hemodynamic study of the issue, concluding that increasing left ventricular diastolic pressure can increase measurements of FFR, particularly in patients with FFR<0.80 and lower blood pressure.