Optimizing Cardiac CT Protocols for Comprehensive Acquisition Prior to Percutaneous MV and TV Repair/Replacement.

Clinical trials of transcatheter mitral valve and tricuspid valve repair and replacement devices have begun in earnest, with the ultimate goal of providing definitive, nonsurgical treatment for the millions of patients with severe, symptomatic regurgitation, many of whom are too high risk or inoperable for a surgical approach. Computed tomography (CT) angiography offers the potential for detailed anatomic assessment in this patient population, but its optimal implementation for patients with mitral and tricuspid disease requires patient-centered protocol specification reflecting the goal of the scan, an understanding of complex anatomy and pathophysiology, and particulars of CT scanner capabilities. In this paper, the need for new interventional approaches to mitral and tricuspid valve disease is discussed, followed by a detailed review of how to perform a high-quality CT angiography examination, taking into consideration scanner- and patient-specific variables when preparing a pre-mitral or tricuspid protocol. The many possible clinical challenges affecting the performance of cardiac and vascular CT angiography for pre-procedure mitral and tricuspid repair/replacement are reviewed and specific tips, trouble-shooting approaches, and recommendations are provided for how to conduct the best-quality study, be it at an experienced imaging center with the most advanced scanner or at a novice center using an earlier generation CT platform.

Virtual septal myectomy for preoperative planning in hypertrophic cardiomyopathy.

OBJECTIVE: Although septal myectomy (SM) is the preferred treatment for medication-refractory obstructive hypertrophic cardiomyopathy, the procedure remains subjective. We have developed a virtual myectomy (VM) technique using 3-dimensional reconstruction of gated cardiac computed tomography (CT) to assist intraoperative objective assessment of the adequacy of the resection. METHODS: We retrospectively reviewed patients 15 patients who underwent a SM guided by preoperative VM at our program between March 2016 and July 2017. Gated cardiac CT was performed to allow delineation of the left ventricular (LV) myocardium at end-diastole to replicate the cardioplegic myocardial arrest (90%-95% RR interval). SM was performed to attain resection volume predicted by VM. Retrospective, blinded VM also was performed with fixed parameters to determine relationship between ideal (VM1) and conservative (VM2) VM and actual resection. RESULTS: Mean patient age was 52.1 ± 10.6 years, 27% were male, and 80% had New York Heart Association class 3 or 4. Preoperative mean peak LV outflow tract gradient was 79 mm Hg (range 47-82). In-hospital mortality was 0%. Mean postoperative LV outflow tract gradient was 13 mm Hg (11-19). Gated cardiac CT was performed with mean phase 94% (86%-98%). Mean total LV myocardial volume was 226 cm3 (146-365) and volume of the asymmetric portion of the LV was 19 cm3 (5.2-48.8). Actual surgical resection volume was 6.2 ± 1.7 cm3. Retrospective VM1 and VM2 performed postoperatively blinded to surgical results were 12.8 cm3 (4.8-29.23) and 6.7 cm3 (3.5-13.2), showing a modest correlation (R1 = 0.44, R2 = 0.56) with actual myectomy. CONCLUSIONS: Three-dimensional CT and VM can be a viable addition to preoperative assessment of patients with obstructive hypertrophic cardiomyopathy.

Comparison between Three-Dimensional Echocardiography and Computed Tomography for Comprehensive Tricuspid Annulus and Valve Assessment in Severe Tricuspid Regurgitation: Implications for Tricuspid Regurgitation Grading and Transcatheter Therapies.

BACKGROUND: Tricuspid valve imaging is frequently challenging and requires the use of multiple modalities. Knowledge of limitations and methodologic discrepancies among different imaging techniques is crucial for planning transcatheter valve interventions. METHODS: Thirty-eight patients with severe symptomatic tricuspid regurgitation were included in this retrospective analysis. Tricuspid annulus (TA) measurements were made during mid-diastole using three-dimensional (3D) transthoracic echocardiographic direct planimetry (TTE_direct) and transesophageal echocardiographic direct planimetry (TEE_direct). Moreover, a semiautomated software was used to generate two-dimensional (2D) and 3D perimeter and area on transesophageal echocardiography (TEE) images. Both methods were compared with direct computed tomographic planimetry (CT_direct) and cubic spline interpolation (CT_indirect). The different TA values were used to calculate the effective regurgitant orifice area and compared with 3D Doppler vena contracta area. For tricuspid valve area TEE_direct and CT_direct as well as CT_indirect were measured. RESULTS: Agreement between TEE and computed tomography (CT) for TA sizing was obtained using semiautomated methods (3D TEE_indirect and CT_indirect). TTE_direct was overall less reliable compared with CT. TA area quantified by TEE_direct was 25% (difference 305 ± 238 mm2, P < .001, R = 0.9) and 19% (166 ± 247 mm2, P < .001, R = 0.89) smaller compared with CT_direct and CT_indirect, respectively. TA perimeter measurements by TEE_direct differed by 11% compared with CT_direct (12 ± 11 mm, P < .001, R = 0.87) and 3D CT_indirect (12 ± 11 mm, P < .001, R = 0.88), and 9% compared with 2D CT_indirect (7 ± 11 mm, P = .002, R = 0.87). TEE_direct of the TA allows the most accurate calculation of effective regurgitant orifice area compared with 3D vena contracta area (-8 ± 62 mm2, P = .50, R = 0.85). Tricuspid valve area by CT_indirect best correlated with conventional TEE_direct (80 ± 250 mm2, P = .11, R = 0.80). CONCLUSIONS: In patients with severe tricuspid regurgitation, semiautomated indirect planimetry results in high agreement between TEE and CT for TA sizing and measurement of the tricuspid valve area. TEE_direct of the TA allows the most accurate measurement of diastolic stroke volume for the calculation of regurgitation severity compared with 3D vena contracta area.

Practical determination of aortic valve calcium volume score on contrast-enhanced computed tomography prior to transcatheter aortic valve replacement and impact on paravalvular regurgitation: Elucidating optimal threshold cutoffs.

BACKGROUND: The threshold for the optimal computed tomography (CT) number in Hounsfield Units (HU) to quantify aortic valvular calcium on contrast-enhanced scans has not been standardized. Our aim was to find the most accurate threshold to predict paravalvular regurgitation (PVR) after transcatheter aortic valve replacement (TAVR). METHODS: 104 patients who underwent TAVR with the CoreValve prosthesis were studied retrospectively. Luminal attenuation (LA) in HU was measured at the level of the aortic annulus. Calcium volume score for the aortic valvular complex was measured using 6 threshold cutoffs (650 HU, 850 HU, LA × 1.25, LA × 1.5, LA+50, LA+100). Receiver-operating characteristic (ROC) analysis was performed to assess the predictive value for > mild PVR (n = 16). Multivariable analysis was performed to determine the accuracy to predict > mild PVR after adjustment for depth and perimeter oversizing. RESULTS: ROC analysis showed lower area under the curve (AUC) values for fixed threshold cutoffs (650 or 850 HU) compared to thresholds relative to LA. The LA+100 threshold had the highest AUC (0.81), and AUC was higher than all studied protocols, other than the LA x 1.25 and LA + 50 protocols, where the difference approached statistical significance (p = 0.05, and 0.068, respectively). Multivariable analysis showed calcium volume determined by the LAx1.25, LAx1.5, LA+50, and LA+ 100 HU protocols to independently predict PVR. CONCLUSIONS: Calcium volume scoring thresholds which are relative to LA are more predictive of PVR post-TAVR than those which use fixed cutoffs. A threshold of LA+100 HU had the highest predictive value.

Practical considerations for optimizing cardiac computed tomography protocols for comprehensive acquisition prior to transcatheter aortic valve replacement.

Transcatheter aortic valve replacement (TAVR) is performed frequently in patients with severe, symptomatic aortic stenosis who are at high risk or inoperable for open surgical aortic valve replacement. Computed tomography angiography (CTA) has become the gold standard imaging modality for pre-TAVR cardiac anatomic and vascular access assessment. Traditionally, cardiac CTA has been most frequently used for assessment of coronary artery stenosis, and scanning protocols have generally been tailored for this purpose. Pre-TAVR CTA has different goals than coronary CTA and the high prevalence of chronic kidney disease in the TAVR patient population creates a particular need to optimize protocols for a reduction in iodinated contrast volume. This document reviews details which allow the physician to tailor CTA examinations to maximize image quality and minimize harm, while factoring in multiple patient and scanner variables which must be considered in customizing a pre-TAVR protocol.

Very low intravenous contrast volume protocol for computed tomography angiography providing comprehensive cardiac and vascular assessment prior to transcatheter aortic valve replacement in patients with chronic kidney disease.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is a lifesaving procedure for many patients high risk for surgical aortic valve replacement. The prevalence of chronic kidney disease (CKD) is high in this population, and thus a very low contrast volume (VLCV) computed tomography angiography (CTA) protocol providing comprehensive cardiac and vascular imaging would be valuable. METHODS: 52 patients with severe, symptomatic aortic valve disease, undergoing pre-TAVR CTA assessment from 2013-4 at Columbia University Medical Center were studied, including all 26 patients with CKD (eGFR<30 mL/min) who underwent a novel VLCV protocol (20 mL of iohexol at 2.5 mL/s), and 26 standard-contrast-volume (SCV) protocol patients. Using a 320-slice volumetric scanner, the protocol included ECG-gated volume scanning of the aortic root followed by medium-pitch helical vascular scanning through the femoral arteries. Two experienced cardiologists performed aortic annulus and root measurements. Vascular image quality was assessed by two radiologists using a 4-point scale. RESULTS: VLCV patients had mean (±SD) age 86 ± 6.5, BMI 23.9 ± 3.4 kg/m(2) with 54% men; SCV patients age 83 ± 8.8, BMI 28.7 ± 5.3 kg/m(2), 65% men. There was excellent intra- and inter-observer agreement for annular and root measurements, and excellent agreement with 3D-transesophageal echocardiographic measurements. Both radiologists found diagnostic-quality vascular imaging in 96% of VLCV and 100% of SCV cases, with excellent inter-observer agreement. CONCLUSIONS: This study is the first of its kind to report the feasibility and reproducibility of measurements for a VLCV protocol for comprehensive pre-TAVR CTA. There was excellent agreement of cardiac measurements and almost all studies were diagnostic quality for vascular access assessment.

Quantity and location of aortic valve complex calcification predicts severity and location of paravalvular regurgitation and frequency of post-dilation after balloon-expandable transcatheter aortic valve replacement.

OBJECTIVES: This study sought to determine the impact of quantity and location of aortic valve calcification (AVC) on paravalvular regurgitation (PVR) and rates of post-dilation (PD) immediately after transcatheter aortic valve replacement (TAVR). BACKGROUND: The impact of AVC in different locations within the aortic valve complex is incompletely understood. METHODS: This study analyzed 150 patients with severe, symptomatic aortic stenosis who underwent TAVR. Total AVC volume scores were calculated from contrast-enhanced multidetector row computed tomography imaging. AVC was divided by leaflet sector and region (Leaflet, Annulus, left ventricular outflow tract [LVOT]), and a combination of LVOT and Annulus (AnnulusLVOT). Asymmetry was assessed. Receiver-operating characteristic analysis was performed with greater than or equal to mild PVR and PD as classification variables. Logistic regression was performed. RESULTS: Quantity of and asymmetry of AVC for all regions of the aortic valve complex predicted greater than or equal to mild PVR by receiver-operating characteristic analysis (area under the curve = 0.635 to 0.689), except Leaflet asymmetry. Receiver-operating characteristic analysis for PD was significant for quantity and asymmetry of AVC in all regions, with higher area under the curve values than for PVR (area under the curve = 0.648 to 0.741). On multivariable analysis, Leaflet and AnnulusLVOT calcification were independent predictors of both PVR and PD regardless of multidetector row computed tomography area cover index. CONCLUSIONS: Quantity and asymmetry of AVC in all regions of the aortic valve complex predict greater than or equal to mild PVR and performance of PD, with the exception of Leaflet asymmetry. Quantity of AnnulusLVOT and Leaflet calcification independently predict PVR and PD when taking into account multidetector row computed tomography area cover index.

Mortality in primary and secondary myocarditis.

BACKGROUND: Lymphocytic myocarditis presents as a primary disorder or in association with a systemic disease. Whether primary and secondary myocarditis have the same prognosis is unknown. METHODS: Patients (n = 171) referred to the Johns Hopkins Cardiomyopathy service from 1984 to 1998 with newly diagnosed cardiomyopathy were observed for an average of 5.9 years after an original diagnosis of biopsy-proven myocarditis or until reaching the end point of death. Giant-cell myocarditis was excluded from this study. Myocarditis was classified as secondary when a systemic disease was present at the time of presentation; otherwise, myocarditis was classified as primary. Survival rates among patients with primary and secondary myocarditis were compared with Kaplan-Meier analysis and Cox proportional hazard models incorporating clinical variables, including baseline hemodynamics and treatment with immunosuppressive therapy. RESULTS: The mortality rate associated with secondary myocarditis varied substantially depending on the underlying systemic disorder. Peripartum myocarditis, when compared with idiopathic myocarditis, had a reduced mortality rate (relative hazard, 0.23 [0.06-0.98]; P <.05), which was attenuated after controlling for confounding variables (relative hazard, 0.62 [0.13-2.98]; P =.55). In contrast, human immunodeficiency virus myocarditis had a particularly poor prognosis (relative hazard, 6.70 [3.51-12.79]; P <.05), even after controlling for confounding variables. Myocarditis associated with systemic inflammatory disorders showed a trend toward increased mortality rate (relative hazard, 2.46 [0.65-9.38]; P =.19). For both primary and secondary myocarditis, advanced age and pulmonary hypertension were important clinical predictors of death. CONCLUSIONS: The prognosis of patients with secondary myocarditis, when compared with patients with idiopathic myocarditis, seems most affected by the primary disease process.