Concomitant mitral annular calcification and severe aortic stenosis: prevalence, characteristics and outcome following transcatheter aortic valve replacement.

AIMS: Calcified aortic stenosis (AS) and mitral annular calcification (MAC) have certain similar etiology and pathophysiological mechanisms. MAC is frequently encountered in pre-procedural computed tomography (CT) imaging of patients that undergo transcatheter aortic valve replacement (TAVR), but its prognostic implications for these patients have not been thoroughly investigated. This study sought to evaluate the prevalence of MAC among patients with severe AS and to assess the clinical implications of MAC on these patients during and following TAVR. METHODS AND RESULTS: Consecutive patients that underwent TAVR were compared according to the existence of MAC and its severity in pre-TAVR CT scans. From the entire cohort of 761 patients, 49.3% had MAC, and 50.7% did not have MAC. Mild MAC was present in 231 patients (30.4%), moderate MAC in 72 patients (9.5%), and severe MAC in 72 patients (9.5%). Thirty-day mortality and major complications were similar between patients with and without MAC. In a multivariable survival analysis, severe MAC was found to be an independent strong predictor of overall mortality following TAVR (all-cause mortality: hazards ratio [HR] 1.95, 95% confidence interval [CI] 1.24-3.07, P = 0.004; cardiovascular mortality: HR 2.35, 95% CI 1.19-4.66; P = 0.01). Severe MAC was also found to be an independent strong predictor of new permanent pacemaker implantation (PPI) after TAVR (OR 2.83, 95% CI 1.08-7.47; P = 0.03). CONCLUSION: Half of the patients with severe AS evaluated for TAVR were found to have MAC. Severe MAC is associated with increased all-cause and cardiovascular mortality and with conduction abnormalities following TAVR and should be included in future risk stratification models for TAVR.

Epidemiology, Traditional and Novel Risk Factors in Coronary Artery Disease.

Coronary artery disease (CAD) mortality has been declining in the United States and in regions where health care systems are relatively advanced. Still, CAD remains the number one cause of death in both men and women in the United States, and coronary events have increased in women. Many traditional risk factors for CAD are related to lifestyle, and preventative treatment can be tailored to modifying specific factors. Novel risk factors also may contribute to CAD. Finally, as the risk for CAD is largely understood to be inherited, further genetic testing should play a role in preventative treatment of the disease.

Use of regadenoson for measurement of fractional flow reserve.

OBJECTIVE: To compare the use of regadenoson to adenosine for measurement of fractional flow reserve (FFR). BACKGROUND: FFR is an accepted method to assess the functional significance of intermediate coronary artery stenoses and uses adenosine to induce maximal hyperemia. The use of the selective A2a receptor agonist regadenoson for FFR is not established. METHODS: Fifty-seven patients undergoing clinically indicated FFR assessment of intermediate coronary stenoses were included. For the initial assessment of FFR, hyperemia was achieved by a standard intravenous adenosine infusion (140 mcg/kg/min). After a washout period of 10 min, FFR was reassessed using regadenoson as a single 0.4 mg intravenous bolus. FFR measurements were recorded at baseline and following maximal hyperemia with both agents. RESULTS: Mean age was 57 ± 8 years and 47 were male. Sixty coronary lesions were evaluated and were located in the left anterior descending in 34, the left circumflex in 9, right coronary in 15, and left main coronary artery in 2. Mean ( ± SD) FFR following adenosine and regadenoson was 0.79 ( ± 0.09) and 0.79 (±0.09), respectively, P = NS. Time to FFR nadir was shorter with regadenoson compared to adenosine, 36.6 ± 24 versus 66 ± 0.19 sec, P < 0.0001, respectively. No patients experienced any significant side effects related to regadenoson. CONCLUSIONS: Regadenoson is a viable alternative to intravenous adenosine for achieving maximal hyperemia during FFR assessment. Compared to adenosine, regadenoson has a similar hemodynamic response, achieves more rapid hyperemia, is easier to use, and has an excellent side-effect profile.

Usefulness of Thoracic Aortic Calcium to Predict 1-Year Mortality After Transcatheter Aortic Valve Implantation.

In patients who underwent transcatheter aortic valve implantation (TAVI), vascular disease is associated with increased risk of mortality. Thoracic aortic calcification (TAC), an objective surrogate of vascular disease, could be a predictor of mortality after TAVI. We aimed to analyze the association between TAC burden and 1-year all-cause mortality in patients who underwent TAVI in a US population. From July 2015 through July 2017, a retrospective review of TAVI procedures was performed at Baylor Scott & White-The Heart Hospital, Plano, Texas. Patients were analyzed for comorbidities, cardiac risk factors, and 30-day and 1-year all-cause mortality. Restricted cubic splines analysis was used to define low, moderate, and high TAC categories. The association between TAC and survival was evaluated using unadjusted and adjusted Cox models. A total of 431 TAVI procedures were performed, of which TAC was measured in 374 (81%) patients. Median (interquartile range) age was 82 (77, 87) years, and 51% were male. Median (interquartile range) STS PROM was 5.6 (4.1, 8.2) %. Overall 30-day and 1-year all-cause mortality was 1% and 10%, respectively. TAC was categorized as low (<1.6 cm3), moderate (1.6 to 2.9 cm3), and high (>2.9 cm3). At 1 year, all-cause mortality was 16% in patients with high TAC compared with 6% in the low and moderate TAC categories (p = 0.008). Unadjusted and adjusted Cox regression analysis showed a significant increase in mortality for patients with high TAC compared with low TAC (hazard ratio 2.98, 95% confidence interval [1.34-6.63]), but not significant compared with moderate TAC group. TAC is a predictor of late mortality after TAVI. In conclusion, adding TAC to preoperative evaluation may provide an objective, reproducible, and potentially widely available tool that can help in shared decision-making.

Total and individual coronary artery calcium scores as independent predictors of mortality in hemodialysis patients.

Many traditional and nontraditional risk factors contribute to vascular calcification among maintenance hemodialysis (MHD) patients. It is not clear whether coronary artery calcification (CAC) delineates a higher mortality risk independent of known risk factors. We examined 6-year (10/2001-9/2007) survival of 166 MHD patients, aged 53 +/- 13 years, with baseline CAC scores. Patients were grouped into four CAC groups: 0, 1-100, 101-400, and 400+. The 101-400 and 400+ groups were associated with a significantly higher adjusted risk of death than CAC 0 with hazard ratios (HR) 8.5 (95% CI: 1.1-48.1, p = 0.02) and 13.3 (95% CI: 1.3-65.1, p = 0.01), respectively, independent of demographics, comorbidity, lipids and other cardiovascular risks, surrogates of bone disease, nutritional and inflammatory markers and dialysis dose. Total CAC [HR 6.7 (1.1-21.5, p = 0.03)] followed by the presence of CAC in the left main [4.6 (2.2-9.8, p = 0.001)] and left anterior descending artery [4.3 (2.1-14.2, p = 0.001)] were strong independent predictors of mortality even after adjusting for above covariates. Total and vessel-specific CAC predict mortality in MHD patients independent of traditional and nontraditional risk factors.

Aortic coarctation by cardiovascular CT angiography.

The patient is a 12-year-old boy who underwent prospectively gated step-and-shoot chest CT (computed tomographic) angiography with a 64-multislice CT scanner (64-MSCT) for a preliminary diagnosis of coarctation of aorta. The data was acquired in a manner to significantly minimize radiation to the patient, including use of 80 kVp (rather than 120 kVp, much more commonly employed in cardiac CT), low mA (120 mA, rather than typical 400 mA), and prospective acquisition using a VCT 64 detector scanner (General Electric, Milwaukee, WI) (Figs. 1 and 2). Total radiation dose was 0.9 mSv, despite imaging from sternal notch to liver. Findings included dilated ascending aorta (43 mm diameter) and a total coarctation of descending aorta with very well-developed collaterals. The left internal mammary artery and right internal mammary artery were noted to be very large (7 mm diameter).

Cardiovascular computed tomographic angiography evaluation following unsuccessful invasive angiography: the clinical utility of 3D volume rendering.

In an appropriate clinical setting, cardiac CT angiography (CCT) can be used as a safe and effective noninvasive imaging modality for defining coronary arterial anatomy by providing detailed three-dimensional anatomic information that may be difficult to obtain with invasive coronary angiography (ICA). We present a patient where coronary angiography by ICA was unsuccessful and where the subsequent CCT proved to be very useful in providing us relevant information.

Diagnostic accuracy of 64 multidetector computed tomographic angiography in peripheral vascular disease.

BACKGROUND: Previous studies of multidetector CT (MDCT) of the lower extremities for the detection of peripheral vascular disease showed high diagnostic accuracy but were performed with older generation systems. OBJECTIVE: The purpose of this study was to evaluate the diagnostic accuracy of 64 MDCT for the detection of hemodynamically significant disease within the lower extremity peripheral vasculature as compared to digital subtraction angiography (DSA). METHODS: Twenty-eight consecutive patients with symptomatic lower extremity intermittent claudication and an abnormal ankle-brachial index (ABI; less than 0.9) were evaluated by both 64 MDCT and DSA. Axial images were acquired with a 64 multidetector general electric light speed VCT scanner. Images were analyzed using a GE Advantage workstation (AW 4.3) capable of advanced image processing and manipulation. The aorto-iliac and lower extremity arteries were divided into 15 segments per limb (30 segments per patient). Eight hundred forty segments were analyzed in a blinded fashion by physicians with level III CT certification. Segments were classified as grade I (<10% stenosis), grade II (10-49%), grade III (50-99%), and grade IV (occlusion). RESULTS: For all segments evaluated, the overall diagnostic accuracy for detecting grade III and IV lesions was 98% with a sensitivity of 99% and a specificity of 98%. For the aorto-iliac segments, the diagnostic accuracy was 98% with a sensitivity of 100% and a specificity of 99%. For the femoro-popliteal segments, the overall accuracy was 98% with a sensitivity of 100% and a specificity of 99%. For the infra-popliteal segments, the overall accuracy was 98% with a sensitivity of 97% and a specificity of 99%. One segment could not be visualized by MDCT compared to 49 segments that could not be visualized by DSA. CONCLUSIONS: This study demonstrates excellent diagnostic accuracy of 64 MDCT in the detection of hemodynamically significant disease of the lower extremities. More segments are visualized using 64 MDCT than DSA, allowing more complete visualization of the vascular tree. CT angiography should be considered in the diagnostic evaluation of symptomatic patients with peripheral vascular disease.

Right common iliac aneurysm by peripheral computed tomographic angiography.

This is a 77-year-old diabetic woman with history of claudication (Rutherford Category 2). Due to fear of underestimating disease with ankle-brachial index in a person with diabetes and advancing age, a CT angiogram was performed. The right common iliac artery had aneurysmal disease (3.4 cm) and a thrombus of right internal iliac artery. There was also a 40% stenosis of right external iliac artery and a left subtotal internal iliac stenosis at the origin. Given it's non-invasive nature and high diagnostic accuracy, CTA is poised to become the noninvasive test of choice in patients with suspected PAD or in patients at risk for obstructive vascular disease.

Comparison of coronary artery calcium scores between electron beam computed tomography and 64-multidetector computed tomographic scanner.

OBJECTIVE: Because almost all data currently available with coronary calcium scanning are from electron beam tomography (EBT), we assessed whether scores obtained with 64-multidetector computed tomography (CT; MDCT) are similar. We evaluated the interscan variation in coronary artery calcium (CAC), Agatston score (AS), and volume score (VS) between EBT and 64-MDCT (VCT; GE, Milwaukee, Wis). MATERIALS AND METHODS: One hundred two patients (mean age, 61.1 years; 27 women) underwent dual CAC scanning with both EBT and 64-MDCT. The AS and VS were measured with the Aquarius workstation (TeraRecon, Inc, San Mateo, Calif). The correlation coefficient, Bland-Altman analysis, interscanner variation, and agreement in AS and VS scores between EBT and 64-MDCT were computed. RESULTS: Interscan agreement for presence of CAC was 99%. Median values were 286 and 268 mm for AS and 243 and 213 mm for VS with EBT and 64-MDCT, respectively (P > 0.05). There was significant linear relationship between scores from the 2 scanners (R = 0.98 in AS and R = 0.99 in VS; P < 0.001). The interscanner variability between EBT and 64-MDCT was 20.9% and 17.6% in AS and VS, respectively (P = NS). Bland-Altman analysis demonstrated a mean difference in scores of 8.3% for AS and 7.8% by VS. When compared with EBT, there were larger and more prevalent motion artifacts (P < 0.001) and larger mean Hounsfield units using 64-MDCT (P < 0.001). CONCLUSIONS: At CAC scanning, 64-MDCT and EBT were comparable in AS and VS. The interscan variability between scanners is similar to interscan variability of 2 calcium scores done on the same equipment. However, heart rate control was achieved for this study for calcium scores. Whether these results are repeatable without heart rate control needs to be further assessed.

Impact of Mitral Stenosis on Survival in Patients Undergoing Isolated Transcatheter Aortic Valve Implantation.

This study was performed to investigate the prevalence and impact on survival of baseline mitral stenosis (MS) in patients who underwent transcatheter aortic valve implantation (TAVI) due to the presence of severe symptomatic aortic stenosis. This retrospective study included 928 consecutive patients with severe, symptomatic aortic stenosis who underwent TAVI in 2 institutions, from January 2012 to August 2016. Mean follow-up was 40.8 ± 13.9 months. Based on the mean mitral gradient (MMG) at baseline, 3 groups were identified: MMG <5 mm Hg (n = 737, 81.7%); MMG ≥5 and <10 mm Hg (n = 147, 16.3%); MMG ≥10 mm Hg (n = 17, 1.9%). These latter were more frequently women, with a smaller body surface area, a higher prevalence of atrial fibrillation, chronic obstructive pulmonary disease, and previous history of coronary-artery bypass graft/percutaneous coronary intervention. At baseline, patients with MMG ≥10 mm Hg compared with ≥5 and <10 mm Hg and <5 mm Hg patients had a lower mitral valve area (2.4 ± 0.94 vs 2.1 ± 0.86 vs 1.5 ± 0.44 cm2), a lower prevalence of MR ≥2+ (5.9% vs 28.6% and 15.6%, p <0.0001), a higher prevalence of severe mitral annular calcium (70.6% vs 45.6% and 13.0%, p <0.0001) and a higher systolic pulmonary arterial pressure (50.6 ± 12.1 vs 47.2 ± 14.5 and 41.6 ± 14.4, p <0.0001). Despite the low prevalence of MMG ≥10 mm Hg, these patients had higher 5-year mortality compared with the other groups (adjusted hazard ratio 2.91, 95% confidence interval 1.17 to 7.20, p = 0.02). In conclusion, severe calcific MS is uncommon in patients who underwent TAVI. Its presence is associated with higher long-term mortality whereas moderate MS is not.

Effect of patient visualization of coronary calcium by electron beam computed tomography on changes in beneficial lifestyle behaviors.

Despite convincing data demonstrating the benefits of aspirin (ASA), exercise, and dietary changes for both primary and secondary prevention of coronary heart disease, they remain underused. In this study, we assess whether higher coronary artery calcium (CAC) scores determined by electron beam computed tomography (EBCT) are associated with beneficial lifestyle behaviors in asymptomatic individuals. A total of 980 asymptomatic patients referred for EBCT risk assessment by their primary physician were sent a survey questioning them about health behaviors. We evaluated long-term ASA utilization, exercise, and dietary changes based on CAC using multivariable analysis. The study population consisted of 980 individuals (78% men, mean age 60 +/- 8 years) who were followed for a mean of 3 +/- 2 years after an initial EBCT scan. Overall, ASA initiation was lowest (29%) among those with CAC = 0, and gradually increased with higher CAC scores (1 to 99, 55%; 100 to 399, 61%; > or =400, 63%; p <0.001 for trend). Similarly, dietary changes and exercise were lowest (33% and 44%, respectively) among those with CAC = 0 and gradually increased with higher CAC scores (1 to 99, 40%; 100 to 399, 58%; > or =400, 56%; p <0.001 for trend for dietary changes; and 1 to 99, 62%; 100 to 399, 63%; > or =400, 67%; p <0.001 for trend for exercise). In multivariable analysis, greater baseline CAC was strongly associated with initiation of ASA therapy, dietary changes, and increased exercise. In conclusion, in addition to risk stratification of asymptomatic individuals, determination of CAC may also improve utilization of ASA therapy and behavioral modification.

Validation of a low-dose contrast 64-slice cardiac computed tomography angiography protocol for aortic valve annulus sizing.

Cardiac computed tomography angiography (CCTA) is the gold standard for accurately sizing the aortic valve annulus prior to aortic valve replacement. A reduction of contrast volume administered for CCTA, without sacrificing image quality, is desirable. Signal-to-noise ratio represents final CCTA image quality. Consecutive patients referred to CCTA for aortic valve annulus sizing were retrospectively analyzed. Patients were grouped into a low-dose contrast (LDCT) group and traditional dose contrast (TDCT) group. In the LDCT group, contrast dose was <50% of the maximal allowable dose (3.7 × estimated glomerular filtration rate). Guided by a time-density curve, the contrast was administered in a two-stage infusion, and retrospectively gated images were acquired with a 64-multidetector computed tomography scanner. Out of 123 patients (age 80 ± 9 years; 46% female), 65 (52.9%) underwent LDCT and 58 (47.2%) underwent TDCT. Contrast volume was significantly lower in the LDCT group (LDCT 41.2 ± 9.8 vs TDCT 76.2 ± 14.2 mL; P < 0.001). The signal-to-noise ratio of the aortic root was 10.4 ± 4.1 for the LDCT group and 8.4 ± 3.3 for the TDCT group (P = 0.004). Aortic root dimensions could be measured in both LDCT and TDCT groups. In conclusion, LDCT with 64-slice CCTA can effectively size the aortic valve annulus to direct aortic valve replacement while offering reduced contrast exposure.

Clinical Leaflet Thrombosis in Transcatheter and Surgical Bioprosthetic Aortic Valves by Four-Dimensional Computed Tomography.

BACKGROUND: The incidence of leaflet thrombosis after transcatheter aortic valve replacement (TAVR) with active surveillance by four-dimensional computed tomography (4DCT) ranges from 7% to 14%. The incidence of leaflet thrombosis when 4DCT is performed for clinical and echocardiographic indications is unknown. METHODS: All patients with prior TAVR or surgical aortic valve replacement (SAVR) who underwent evaluation between October 2015 and January 2017 at our institution and had clinical or echocardiographic indications of leaflet thrombosis were evaluated by 4DCT. Indications for 4DCT by echocardiography included (1) interval increase in mean gradient of 10 mm Hg or more, (2) interval decrease in ejection fraction of 10% or more, (3) thrombus seen on transthoracic echocardiography, (4) persistent or increasing paravalvular leak, or (5) valve dehiscence or thickened leaflets seen on transthoracic echocardiography. Clinical indicators were (1) stroke, (2) transient ischemic attack, or (3) new or worsening heart failure. RESULTS: During the study period, 612 patients underwent TAVR, and 101 patients (55 TAVR; 46 SAVR) met the criteria for 4DCT imaging. Leaflet thrombosis was seen in 17 of 55 TAVR patients (30.9%) and 15 of 46 SAVR patients (32.6%). Follow-up imaging with 4DCT after treatment with anticoagulation showed improvement or resolution in thrombus burden and leaflet excursion in all TAVR patients and in two-thirds of SAVR patients. CONCLUSIONS: One-third of patients with clinical or echocardiographic indications suggestive of leaflet thrombosis were found to have evidence of leaflet thrombosis using 4DCT. This allowed tailored anticoagulation therapy with resolution of the thrombus in most patients and avoiding unnecessary anticoagulation in the remaining two-thirds of patients.

Cardiac CT angiography (CTA) and nuclear myocardial perfusion imaging (MPI)-a comparison in detecting significant coronary artery disease.

RATIONALE AND OBJECTIVES: Endowed with sufficient diagnostic accuracy, electron beam computed tomography angiography (CTA) is being increasingly used to evaluate coronary arteries. However, data on direct comparisons with nuclear myocardial perfusion studies are limited. In this study, we sought to compare the accuracies of CTA and myocardial perfusion imaging (MPI) for identifying symptomatic patients with hemodynamically significant obstructive coronary artery disease (CAD). MATERIALS AND METHODS: In a single-center study, symptomatic outpatients who were scheduled for cardiac catheterization were prospectively enrolled. Only patients with exertional angina or dyspnea were included. After fulfilling the inclusion criteria, 30 patients were enrolled in the study (mean age 54 +/- 9 years and 70% males). Patients underwent MPI, CTA including coronary artery calcification (CAC) measure, and invasive coronary angiography for evaluation of obstructive coronary artery disease. Significant CAD was defined as >50% left main artery stenosis or >70% stenosis of any other epicardial vessel by invasive angiography. The sensitivities, specificities and predictive values of MPI, CAC, and CTA were analyzed per patient RESULTS: CTA demonstrated significant higher sensitivity than MPI (95% vs. 81%, P < .05). CTA demonstrated significantly higher specificity than both MPI (89% versus 78%, P = .04) and CAC (56%, P = .002). CTA also performed better in a per-vessel analysis (sensitivity 94%, specificity 96%) than both nuclear and CAC. There were no significant differences between the sensitivities and specificities of MPI and CAC. CONCLUSION: CTA accurately detects obstructive CAD in symptomatic patients and may be more accurate than MPI or CAC assessment. Larger studies in a more diverse population are needed.

Coronary calcium scanning in geriatric cardiology.

Coronary artery disease (CAD) is prevalent in the elderly, often leads to disability, and is the number one cause of death in this population. Older adults represent an increasingly important and challenging subset of the population with CAD. They are more likely to have comorbid conditions, atypical presentations, and unfavorable outcomes than their younger counterparts. The available data suggest that standard pharmacologic, thrombolytic, and definitive revascularization techniques have important roles in the treatment of geriatric patients but have been underutilized. Consequently, strategies for optimizing the prevention and treatment of CAD in the elderly are important from both the individual and societal perspectives. Coronary artery calcium has been shown to be highly specific for atherosclerosis, occurring only in the intima of the coronary arteries. There is evidence to show that elevated coronary calcium scores are predictive of future cardiovascular events, both independently of and incrementally to conventional cardiovascular risk factors. This article will review such a screening method, namely coronary calcium scanning, in the field of geriatric cardiology.

Pathologic confirmation of valve thrombosis detected by four-dimensional computed tomography following valve-in-valve transcatheter aortic valve replacement.

A major concern regarding transcatheter aortic valve replacement (TAVR) is leaflet thrombosis. Four-dimensional computed tomography (4D-CT) is the preferred imaging modality to evaluate patients with suspected valve thrombosis. To date, the abnormal findings visualized by 4D-CT suggestive of leaflet thrombosis have lacked pathologic confirmation from a surgically explanted valve in a surviving patient. Herein, we provide pathologic confirmation of thrombus formation following surgical explantation of a thrombosed TAVR prosthesis that was initially identified by 4D-CT.