Caged-in: Successful percutaneous closure of left atrial appendage with Watchman-FLX in the presence of proximal thrombus.

Percutaneous mechanical closure of the left atrial appendage (LAA) is a valuable stroke prevention strategy in patients with atrial fibrillation and contraindication to oral anticoagulation. LAA thrombus is a common finding in patients with atrial fibrillation and frequently fails to resolve despite therapeutic anticoagulation. In this scenario, LAA occlusion device implant is generally discouraged due to the high risk of thrombus dislodgement and embolization; however, alternative management options are limited. We report the first case of a successful LAA occlusion device (Watchman-FLX) implant in the presence of a proximal thrombus.

Prevalence and outcome of dual aortic stenosis and cardiac amyloid pathology in patients referred for transcatheter aortic valve implantation.

AIMS: Cardiac amyloidosis is common in elderly patients with aortic stenosis (AS) referred for transcatheter aortic valve implantation (TAVI). We hypothesized that patients with dual aortic stenosis and cardiac amyloid pathology (AS-amyloid) would have different baseline characteristics, periprocedural and mortality outcomes. METHODS AND RESULTS: Patients aged ≥75 with severe AS referred for TAVI at two sites underwent blinded bone scintigraphy prior to intervention (Perugini Grade 0 negative, 1-3 increasingly positive). Baseline assessment included echocardiography, electrocardiogram (ECG), blood tests, 6-min walk test, and health questionnaire, with periprocedural complications and mortality follow-up. Two hundred patients were recruited (aged 85 ± 5 years, 50% male). AS-amyloid was found in 26 (13%): 8 Grade 1, 18 Grade 2. AS-amyloid patients were older (88 ± 5 vs. 85 ± 5 years, P = 0.001), with reduced quality of life (EQ-5D-5L 50 vs. 65, P = 0.04). Left ventricular wall thickness was higher (14 mm vs. 13 mm, P = 0.02), ECG voltages lower (Sokolow-Lyon 1.9 ± 0.7 vs. 2.5 ± 0.9 mV, P = 0.03) with lower voltage/mass ratio (0.017 vs. 0.025 mV/g/m2, P = 0.03). High-sensitivity troponin T and N-terminal pro-brain natriuretic peptide were higher (41 vs. 21 ng/L, P < 0.001; 3702 vs. 1254 ng/L, P = 0.001). Gender, comorbidities, 6-min walk distance, AS severity, prevalence of disproportionate hypertrophy, and post-TAVI complication rates (38% vs. 35%, P = 0.82) were the same. At a median follow-up of 19 (10-27) months, there was no mortality difference (P = 0.71). Transcatheter aortic valve implantation significantly improved outcome in the overall population (P < 0.001) and in those with AS-amyloid (P = 0.03). CONCLUSIONS: AS-amyloid is common and differs from lone AS. Transcatheter aortic valve implantation significantly improved outcome in AS-amyloid, while periprocedural complications and mortality were similar to lone AS, suggesting that TAVI should not be denied to patients with AS-amyloid.

Ultrasound guided vascular access site management and left ventricular pacing are associated with improved outcomes in contemporary transcatheter aortic valve replacement: Insights from the OxTAVI registry.

OBJECTIVES: To identify clinical and procedural practice predictors of avoidable complications during transcatheter aortic valve replacement (TAVR). BACKGROUND: TAVR is evolving as a viable strategy for treatment of aortic stenosis (AS). Vascular complications, major bleeding, or pericardial tamponade may be influenced by procedural practice. METHODS: The Oxford TAVR (OxTAVI) prospective registry was retrospectively analyzed to identify predictors of avoidable procedural complications in a contemporary cohort of transfemoral TAVR between January 2015 and September 2018. The primary endpoint was defined as a hierarchic composite of in-hospital mortality, pericardial effusion/cardiac tamponade, major bleeding, and vascular access complications. Individual components of the primary endpoint have been analyzed separately. RESULTS: Five-hundred-twenty-nine patients underwent transfemoral TAVR using contemporary techniques during the study period and were enrolled in the OxTAVI registry. Female sex and high frailty were associated with a higher risk of death, major bleeding, vascular complication or pericardial tamponade. The use of ultrasound (US) guidance for vascular access management was independently associated with a reduced composite primary endpoint (OR = 0.35, CI:0.14-0.86, p = .02) after adjustment for clinical confounders, largely driven by a threefold reduction in vascular access complication (OR = 0.29, CI:0.15-0.55, p < .001). Performing rapid pacing via the left ventricle guidewire (LV-GW) was associated with a significant decrease in the risk of cardiac tamponade/pericardial effusion (OR = 0.19, CI:0.05-0.66, p = .009). CONCLUSION: US-guided vascular access management and rapid pacing via the LV-GW are important determinants of reduced procedural complications during TAVR.

Paravalvular leak closure under intracardiac echocardiographic guidance.

OBJECTIVES: The objective of this study was to determine the safety and efficacy of intracardiac echocardiography (ICE) to guide percutaneous paravalvular leak (PVL) closure. BACKGROUND: PVL following surgical valve replacement occurs in 2%-15% of patients. Percutaneous treatment is an accepted management strategy in patients deemed to be too high risk for redo surgery. This is most commonly performed with transesophageal (TOE) guidance requiring general anesthesia that both potentially further increase the risk of intervention. ICE can be used to guide intervention, facilitating procedures to be performed under local anesthesia without esophageal intubation potentially making procedures shorter and safer and further enabling the treatment of patients that may have been turned down for intervention. METHODS: All patients that underwent ICE-guided percutaneous transcatheter PVL closure between 2006 and 2016 at the John Radcliffe Hospital, Oxford, United Kingdom were retrospectively analyzed. RESULTS: Twenty-one procedures were performed in 18 patients during the study period. Fourteen patients (77.8%) underwent successful ICE guided PVL closure. There were no ICE-related complications. Eleven patients (78.6%) reported symptomatic improvement of at least one New York Heart Association (NYHA) Class and the remaining 3 patients had no change. No patient demonstrated objective evidence of persistent hemolysis following successful closure. There was one death within 30 days of the procedure and 1 year survival was 71.4%. CONCLUSIONS: Percutaneous paravalvular leak closure guided by ICE without the requirement of general anesthesia is feasible, safe, and associated with acceptable procedural success rates.

Left Atrial Appendage Occlusion: British Cardiovascular Intervention Society and British Heart Rhythm Society Position Statement.

Percutaneous left atrial appendage occlusion aims to reduce the risk of stroke in patients with AF, particularly those who are not good candidates for systemic anticoagulation. The procedure has been studied in large international randomised trials and registries and was approved by the National Institute for Health and Care Excellence in 2014 and by NHS England in 2018. This position statement summarises the evidence for left atrial appendage occlusion and presents the current indications. The options and consensus on best practice for pre-procedure planning, undertaking a safe and effective implant and appropriate post-procedure management and follow-up are described. Standards regarding procedure volume for implant centres and physicians, the role of multidisciplinary teams and audits are highlighted.

Left Atrial Appendage Occlusion: British Cardiovascular Intervention Society and British Heart Rhythm Society Position Statement.

Percutaneous left atrial appendage occlusion aims to reduce the risk of stroke in patients with AF, particularly those who are not good candidates for systemic anticoagulation. The procedure has been studied in large international randomised trials and registries and was approved by the National Institute for Health and Care Excellence in 2014 and by NHS England in 2018. This position statement summarises the evidence for left atrial appendage occlusion and presents the current indications. The options and consensus on best practice for pre-procedure planning, undertaking a safe and effective implant and appropriate post-procedure management and follow-up are described. Standards regarding procedure volume for implant centres and physicians, the role of multidisciplinary teams and audits are highlighted.

Prioritizing echocardiography in Staphylococcus aureus bacteraemia.

OBJECTIVES: Infective endocarditis (IE) is a severe complication in Staphylococcus aureus bacteraemia (SAB) and recent guidelines from the BSAC recommend all patients undergo echocardiography. We assessed the use of echocardiography at a major tertiary referral centre and sought to identify those patients most likely to have positive findings. METHODS: We retrospectively evaluated all cases of SAB at Oxford University Hospitals NHS Trust between September 2006 and August 2011. RESULTS: Three-hundred-and-six out of 668 patients with SAB underwent cardiac imaging on average 9.8 ± 1.3 days from the first culture. Thirty-one patients (10.1%) had echocardiographic evidence of IE. Risk factors for observing evidence of IE on scanning included the presence of prosthetic heart valves (32% versus 4%, P < 0.001) or cardiac rhythm management (CRM) devices (16% versus 3%, P < 0.004). On excluding patients with prosthetic valves or CRM devices from the analysis, no patient with a line-related bacteraemia and only one patient (an intravenous drug user) with no/mild regurgitation on transthoracic echocardiography had echo evidence of IE. CONCLUSIONS: We propose that the use of scarce echocardiography resources could be prioritized. Patients with prosthetic heart valves or a CRM device should receive early cardiological input and transoesophageal echocardiography. In patients with a clearly defined line-related bacteraemia who do not have a prosthetic valve or CRM device or clinical features of IE, response to treatment could be closely monitored and imaging deferred. Patients without a line-related infection or prosthetic valve/device could receive a transthoracic echocardiogram as a screening tool.

Free floating left atrial ball thrombus: a rare cause of stroke.

In the setting of mitral valve stenosis and atrial fibrillation, left atrial ball thrombus is a rare but recognized cause of stroke and can occur even in the presence of therapeutic anticoagulation. This case report highlights the need for echocardiography to rule out treatable cardioembolic substrates for stroke. We report a case of cardioembolic stroke as a result of free floating left atrial ball thrombus presenting as a complication of rheumatic mitral valve disease. This case highlights that, in all patients with a history of structural heart disease, atrial fibrillation, or rheumatic fever, prompt cardiac ultrasound to exclude free floating atrial thrombus is essential.

Impact of afterload and infiltration on coexisting aortic stenosis and transthyretin amyloidosis.

OBJECTIVE: The coexistence of wild-type transthyretin cardiac amyloidosis (ATTR) is common in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI). However, the impact of ATTR and AS on the resultant AS-ATTR is unclear and poses diagnostic and management challenges. We therefore used a multicohort approach to evaluate myocardial structure, function, stress and damage by assessing age-related, afterload-related and amyloid-related remodelling on the resultant AS-ATTR phenotype. METHODS: We compared four samples (n=583): 359 patients with AS, 107 with ATTR (97% Perugini grade 2), 36 with AS-ATTR (92% Perugini grade 2) and 81 age-matched and ethnicity-matched controls. 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scintigraphy was used to diagnose amyloidosis (Perugini grade 1 was excluded). The primary end-point was NT-pro Brain Natriuretic Peptide (BNP) and secondary end-points related to myocardial structure, function and damage. RESULTS: Compared with older age controls, the three disease cohorts had greater cardiac remodelling, worse function and elevated NT-proBNP/high-sensitivity Troponin-T (hsTnT). NT-proBNP was higher in AS-ATTR (2844 (1745, 4635) ng/dL) compared with AS (1294 (1077, 1554)ng/dL; p=0.002) and not significantly different to ATTR (3272 (2552, 4197) ng/dL; p=0.63). Diastology, hsTnT and prevalence of carpal tunnel syndrome were statistically similar between AS-ATTR and ATTR and higher than AS. The left ventricular mass indexed in AS-ATTR was lower than ATTR (139 (112, 167) vs 180 (167, 194) g; p=0.013) and non-significantly different to AS (120 (109, 130) g; p=0.179). CONCLUSIONS: The AS-ATTR phenotype likely reflects an early stage of amyloid infiltration, but the combined insult resembles ATTR. Even after treatment of AS, ATTR-specific therapy is therefore likely to be beneficial.

Intracardiac echocardiography off piste? Closure of the left atrial appendage using ICE and local anesthesia.

Left atrial appendage (LAA) occlusion is increasingly accepted to reduce the risk of stroke in patients with atrial arrhythmia who are unsuitable for routine anticoagulation. It is generally performed under general anesthesia, guided by transoesophageal echocardiography with accurate imaging being essential for correct deployment of the device. We present a case where LAA occlusion was done under local anesthesia in a high-anesthetic risk patient, using novel placement of an intracardiac echo probe via a Mullins sheath in the right ventricular outflow tract and pulmonary artery. This allowed accurate visualization of device deployment in the LAA. This technique may increase the spectrum of patients who may benefit from the procedure and decrease procedure time, fluoroscopy, and procedure-related morbidity.

Prominence of the Eustachian valve in paradoxical embolism.

AIMS: to investigate the relationship between Eustachian valve (EV) length and degree of atrial septal movement in patients with patent foramen ovale (PFO) and presumed paradoxical cerebral embolism. PFO is a well-established risk factor for cryptogenic stroke. However, due to the high prevalence of PFO, many of these are bystanders rather than true pathological entities. Other studies have sought to define which patients with PFO are particularly at risk of cryptogenic stroke by measuring various parameters of right atrial anatomy. We investigated the relationship between EV length and atrial septal movement. METHODS AND RESULTS: measurements of EV length and atrial septal movement were made prospectively from 72 consecutive patients referred to our centre for PFO closure following presumed cryptogenic stroke, by intracardiac phased array echocardiography. The most significant finding from this study was that patients with fewer than 10 mm atrial septal movement had significantly longer EVs than those in whom there was >10 mm septal movement (P = 0.003). The mean EV length with >10 mm septal movement is 6.35 mm, and 13.33 mm with fewer than 10 mm movement. The prevalence of septal movement beyond 10 mm was significantly less in our series than in previously published papers. CONCLUSION: we propose that while a large degree of atrial septal movement significantly increases propensity to cerebral embolism in patients with PFO, its absence does not negate this risk. We have shown that long EV may function independently from atrial septal movement to potentiate paradoxical embolism.

Cardiovascular magnetic resonance facilitates entirely contrast-free transcatheter aortic valve implantation: case report.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is usually planned using contrast-enhanced computed tomography (CT) to determine the suitability of cardiovascular anatomy. Computed tomography for TAVI planning requires the administration of intravenous contrast, which may not be desirable in patients with severely reduced renal function. CASE SUMMARY: We present an unusual case of an 89-year-old patient with an urgent need for treatment of critical, symptomatic aortic stenosis who also had severe chronic kidney disease. We judged that this posed a relative contraindication to the use of intravenous contrast. We designed and implemented a novel, contrast-free cardiovascular magnetic resonance (CMR) protocol and used this to plan all aspects of the procedure. Transcatheter aortic valve implantation was conducted successfully with zero contrast medium administration leading to an excellent clinical result and recovery of renal function. CONCLUSION: Contrast-free CMR appears to be a viable alternative to CT for planning structural aortic valve intervention in the rare cases where intravenous contrast is relatively contraindicated.

Long-term outcomes and periprocedural safety and efficacy of percutaneous left atrial appendage closure in a United Kingdom tertiary center: An 11-year experience.

BACKGROUND: Left atrial appendage occlusion (LAAO) has been widely adopted as a strategy for stroke prevention in patients with atrial fibrillation ineligible for oral anticoagulation. OBJECTIVE: The purpose of this study was to explore longer-term "real-world" safety and efficacy outcomes in patients undergoing LAAO given varied practices in antithrombotic regimens and adoption of same-day discharge. METHODS: Analysis of acute procedural and long-term outcome data was performed for all patients undergoing LAAO implant in a United Kingdom tertiary center over an 11-year period. Rates of adverse events were calculated and compared to predicted rates in historical cohorts according to CHA2DS2-VASc and HAS-BLED scores. RESULTS: Device implantation was attempted in 229 patients, with an acute procedural success rate of 98.2% and low rate of major procedural complications of 2.6% at 30 days, including 1.3% procedure-related mortality. In the last year of enrollment, 75% of patients were discharged on the same day of the procedure. A strategy of early cessation of antithrombotic therapy was adopted, with a low rate of device-related thrombus. Over total follow-up of 889 patient-years, there were low rates of thromboembolic events (2.2/100 patient-years) and of significant bleeding events (intracranial bleed 0.6/100 patient-years; nonprocedural major bleeding 2.3/100 patient-years). CONCLUSION: LAAO with a same-day discharge strategy and early cessation of antiplatelet therapy seems to be safe and effective in reducing the risk of stroke and major bleeding over mean follow-up approaching 4 years. Although these data are reassuring, results from randomized trials with strict shorter periods of postprocedural antithrombotic therapy are eagerly awaited.

Community prevalence, mechanisms and outcome of mitral or tricuspid regurgitation.

OBJECTIVE: The study aims were (1) to identify the community prevalence of moderate or greater mitral or tricuspid regurgitation (MR/TR), (2) to compare subjects identified by population screening with those with known valvular heart disease (VHD), (3) to understand the mechanisms of MR/TR and (4) to assess the rate of valve intervention and long-term outcome. METHODS: Adults aged ≥65 years registered at seven family medicine practices in Oxfordshire, UK were screened for inclusion (n=9504). Subjects with known VHD were identified from hospital records and those without VHD invited to undergo transthoracic echocardiography (TTE) within the Oxford Valvular Heart Disease Population Study (OxVALVE). The study population ultimately comprised 4755 subjects. The severity and aetiology of MR and TR were assessed by integrated comprehensive TTE assessment. RESULTS: The prevalence of moderate or greater MR and TR was 3.5% (95% CI 3.1 to 3.8) and 2.6% (95% CI 2.3 to 2.9), respectively. Primary MR was the most common aetiology (124/203, 61.1%). Almost half of cases were newly diagnosed by screening: MR 98/203 (48.3%), TR 69/155 (44.5%). Subjects diagnosed by screening were less symptomatic, more likely to have primary MR and had a lower incidence of aortic valve disease. Surgical intervention was undertaken in six subjects (2.4%) over a median follow-up of 64 months. Five-year survival was 79.8% in subjects with isolated MR, 84.8% in those with isolated TR, and 59.4% in those with combined MR and TR (p=0.0005). CONCLUSIONS: Moderate or greater MR/TR is common, age-dependent and is underdiagnosed. Current rates of valve intervention are extremely low.

Safety and Operational Efficiency of Restructuring and Redeploying a Transcatheter Aortic Valve Replacement Service During the COVID-19 Pandemic: The Oxford Experience.

BACKGROUND: The risk of nosocomial COVID-19 infection for vulnerable aortic stenosis patients and intensive care resource utilization has led to cardiac surgery deferral. Untreated severe symptomatic aortic stenosis has a dismal prognosis. TAVR offers an attractive alternative to surgery as it is not reliant on intensive care resources. We set out to explore the safety and operational efficiency of restructuring a TAVR service and redeploying it to a new non-surgical site during the COVID-19 pandemic. METHODS: The institutional prospective service database was retrospectively interrogated for the first 50 consecutive elective TAVR cases prior to and after our institution's operational adaptations for the COVID-19 pandemic. Our endpoints were VARC-2 defined procedural complications, 30-day mortality or re-admission and service efficiency metrics. RESULTS: The profile of patients undergoing TAVR during the pandemic was similar to patients undergoing TAVR prior to the pandemic with the exception of a lower mean age (79 vs 82 years, p < 0.01) and median EuroScore II (3.1% vs 4.6%, p = 0.01). The service restructuring and redeployment contributed to the pandemic-mandated operational efficiency with a reduction in the distribution of pre-admission hospital visits (3 vs 3 visits, p < 0.001) and the time taken from TAVR clinic to procedure (26 vs 77 days, p < 0.0001) when compared to the pre-COVID-19 service. No statistically significant difference was noted in peri-procedural complications and 30-day outcomes, while post-operative length of stay was significantly reduced (2 vs 3 days, p < 0.0001) when compared to pre-COVID-19 practice. CONCLUSIONS: TAVR service restructuring and redeployment to align with pandemic-mandated healthcare resource rationalization is safe and feasible.

Procedural Mortality With Transcatheter Aortic Valve Replacement - Balloon Inflation is Associated With Increased Risk.

OBJECTIVES: To assess the impact of balloon use for predilation, valve implantation, or postdilation on in-hospital mortality among patients undergoing transcatheter aortic valve replacement (TAVR). BACKGROUND: TAVR utilizes self-expanding, mechanically expanding, or balloon-expandable valves. Balloon inflation is inherent to deployment of balloon-expandable valves. Balloons may additionally be used with all valve types for pre- and postdilation. The relationships between valve mechanism, balloon use, and in-hospital mortality are not fully characterized. METHODS: Prospective data were collected on 4063 patients undergoing TAVR for aortic stenosis at 4 high-volume centers in the United Kingdom. In-hospital mortality was analyzed according to valve expansion mechanism, use of balloons for pre- and postdilation, and specific cause of death. RESULTS: Mean patient age was 83 ± 8 years. Implanted valves were self expanding (n = 2241; 55%), mechanically expanding (n = 1092; 27%), or balloon expandable (n = 727; 18%). In-hospital death occurred in 66 cases (1.6%). Thirty-six deaths (54.5%) were classified as implantation-related mortalities, with rates of 0.8%, 0.5%, and 1.7% (P=.04) among self-expanding, mechanically expanding, and balloon-expandable technologies, respectively. Patients who underwent balloon inflation at any stage of their procedure (n = 2556; 63%) had significantly higher implantation-related mortality than those who did not (1.3% vs 0.3%, respectively; P<.01). Balloon-expandable valve procedures were associated with significantly higher all-cause mortality (2.6% vs 1.4%; P=.02) and implantation-related mortality (1.7% vs 0.7%; P=.02) than non-balloon-expandable valve procedures. Balloon-related complications accounted for 18 cases (26%) of total in-hospital mortality, including all 12 cases (17.4%) of annular rupture and 5 cases (7.2%) of coronary occlusion. CONCLUSIONS: Balloon use for predilation, valve implantation, or postdilation was associated with an increased mortality risk. Balloon-related complications were the largest contributor to in-hospital mortality, comprising all cases of annular rupture and the majority of coronary occlusion cases.

Prevalence and Outcomes of Concomitant Aortic Stenosis and Cardiac Amyloidosis.

BACKGROUND: Older patients with severe aortic stenosis (AS) are increasingly identified as having cardiac amyloidosis (CA). It is unknown whether concomitant AS-CA has worse outcomes or results in futility of transcatheter aortic valve replacement (TAVR). OBJECTIVES: This study identified clinical characteristics and outcomes of AS-CA compared with lone AS. METHODS: Patients who were referred for TAVR at 3 international sites underwent blinded research core laboratory 99mtechnetium-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) bone scintigraphy (Perugini grade 0: negative; grades 1 to 3: increasingly positive) before intervention. Transthyretin-CA (ATTR) was diagnosed by DPD and absence of a clonal immunoglobulin, and light-chain CA (AL) was diagnosed via tissue biopsy. National registries captured all-cause mortality. RESULTS: A total of 407 patients (age 83.4 ± 6.5 years; 49.8% men) were recruited. DPD was positive in 48 patients (11.8%; grade 1: 3.9% [n = 16]; grade 2/3: 7.9% [n = 32]). AL was diagnosed in 1 patient with grade 1. Patients with grade 2/3 had worse functional capacity, biomarkers (N-terminal pro-brain natriuretic peptide and/or high-sensitivity troponin T), and biventricular remodeling. A clinical score (RAISE) that used left ventricular remodeling (hypertrophy/diastolic dysfunction), age, injury (high-sensitivity troponin T), systemic involvement, and electrical abnormalities (right bundle branch block/low voltages) was developed to predict the presence of AS-CA (area under the curve: 0.86; 95% confidence interval: 0.78 to 0.94; p < 0.001). Decisions by the heart team (DPD-blinded) resulted in TAVR (333 [81.6%]), surgical AVR (10 [2.5%]), or medical management (65 [15.9%]). After a median of 1.7 years, 23% of patients died. One-year mortality was worse in all patients with AS-CA (grade: 1 to 3) than those with lone AS (24.5% vs. 13.9%; p = 0.05). TAVR improved survival versus medical management; AS-CA survival post-TAVR did not differ from lone AS (p = 0.36). CONCLUSIONS: Concomitant pathology of AS-CA is common in older patients with AS and can be predicted clinically. AS-CA has worse clinical presentation and a trend toward worse prognosis, unless treated. Therefore, TAVR should not be withheld in AS-CA.

Identifying Cardiac Amyloid in Aortic Stenosis: ECV Quantification by CT in TAVR Patients.

OBJECTIVES: The purpose of this study was to validate computed tomography measured ECV (ECVCT) as part of routine evaluation for the detection of cardiac amyloid in patients with aortic stenosis (AS)-amyloid. BACKGROUND: AS-amyloid affects 1 in 7 elderly patients referred for transcatheter aortic valve replacement (TAVR). Bone scintigraphy with exclusion of a plasma cell dyscrasia can diagnose transthyretin-related cardiac amyloid noninvasively, for which novel treatments are emerging. Amyloid interstitial expansion increases the myocardial extracellular volume (ECV). METHODS: Patients with severe AS underwent bone scintigraphy (Perugini grade 0, negative; Perugini grades 1 to 3, increasingly positive) and routine TAVR evaluation CT imaging with ECVCT using 3- and 5-min post-contrast acquisitions. Twenty non-AS control patients also had ECVCT performed using the 5-min post-contrast acquisition. RESULTS: A total of 109 patients (43% male; mean age 86 ± 5 years) with severe AS and 20 control subjects were recruited. Sixteen (15%) had AS-amyloid on bone scintigraphy (grade 1, n = 5; grade 2, n = 11). ECVCT was 32 ± 3%, 34 ± 4%, and 43 ± 6% in Perugini grades 0, 1, and 2, respectively (p < 0.001 for trend) with control subjects lower than lone AS (28 ± 2%; p < 0.001). ECVCT accuracy for AS-amyloid detection versus lone AS was 0.87 (0.95 for 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid Perugini grade 2 only), outperforming conventional electrocardiogram and echocardiography parameters. One composite parameter, the voltage/mass ratio, had utility (similar AUC of 0.87 for any cardiac amyloid detection), although in one-third of patients, this could not be calculated due to bundle branch block or ventricular paced rhythm. CONCLUSIONS: ECVCT during routine CT TAVR evaluation can reliably detect AS-amyloid, and the measured ECVCT tracks the degree of infiltration. Another measure of interstitial expansion, the voltage/mass ratio, also performed well.

DPD Quantification in Cardiac Amyloidosis: A Novel Imaging Biomarker.

OBJECTIVES: To assess whether single-photon emission computed tomography (SPECT/CT) quantification of bone scintigraphy would improve diagnostic accuracy and offer a means of quantifying amyloid burden. BACKGROUND: Transthyretin-related cardiac amyloidosis is common and can be diagnosed noninvasively using bone scintigraphy; interpretation, however, relies on planar images. SPECT/CT imaging offers 3-dimensional visualization. METHODS: This was a single-center, retrospective analysis of 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scans reported using the Perugini grading system (0 = negative; 1 to 3 = increasingly positive). Conventional planar quantification techniques (heart/contralateral lung, and heart/whole-body retention ratios) were performed. Heart, adjacent vertebra, paraspinal muscle and liver peak standardized uptake values (SUVpeak) were recorded from SPECT/CT acquisitions. An SUV retention index was also calculated: (cardiac SUVpeak/vertebral SUVpeak) × paraspinal muscle SUVpeak. In a subgroup of patients, SPECT/CT quantification was compared with myocardial extracellular volume quantification by CT imaging (ECVCT). RESULTS: A total of 100 DPD scans were analyzed (patient age 84 ± 9 years; 52% male): 40 were Perugini grade 0, 12 were grade 1, 41 were grade 2, and 7 were grade 3. Cardiac SUVpeak increased from grade 0 to grade 2; however, it plateaued between grades 2 and 3 (p < 0.001). Paraspinal muscle SUVpeak increased with grade (p < 0.001), whereas vertebral SUVpeak decreased (p < 0.001). The composite parameter of SUV retention index overcame the plateauing of the cardiac SUVpeak and increased across all grades (p < 0.001). Cardiac SUVpeak correlated well (r2 = 0.73; p < 0.001) with ECVCT. Both the cardiac SUVpeak and SUV retention index had excellent diagnostic accuracy (area under the curve [AUC]: 0.999). The heart to contralateral lung ratio performed the best of the planar quantification techniques (AUC: 0.987). CONCLUSIONS: SPECT/CT quantification in DPD scintigraphy is possible and outperforms planar quantification techniques. Differentiation of Perugini grade 2 or 3 is confounded by soft tissue uptake, which can be overcome by a composite SUV retention index. This index can help in the diagnosis of cardiac amyloidosis and may offer a means of monitoring response to therapy.