Disease Activity in Mitral Annular Calcification

Transcatheter Mitral Valve Therapies in Patients with Mitral Annular Calcification

Mitral annular calcification is a chronic process involving degeneration and calcium deposition within the fibrous skeleton of the mitral valve annulus, which can lead to mitral valve dysfunction. It can be asymptomatic, or it can have pathologic sequelae leading to cardiovascular morbidity and mortality. Mitral annular calcification is increasingly recognized with the advancement of diagnostic imaging modalities, especially in an era with a growing elderly population. Its presence poses considerable challenges in terms of surgical and transcatheter management. Multiple surgical and transcatheter techniques have been developed to overcome these challenges. New transcatheter technologies are under investigation to tackle this problem.

Contemporary experience with the Commando procedure for anterior mitral anular calcification

Objective

Anterior mitral anular calcification, particularly in radiation heart disease, and previous valve replacement with destroyed intervalvular fibrosa are challenging for prosthesis sizing and placement. The Commando procedure with intervalvular fibrosa reconstruction permits double-valve replacement in these challenging conditions. We referenced outcomes after Commando procedures to standard double-valve replacements.

Methods

From January 2011 to January 2022, 129 Commando procedures and 1191 aortic and mitral double-valve replacements were performed at the Cleveland Clinic, excluding endocarditis. Reasons for the Commando were severe calcification after radiation (n = 67), without radiation (n = 43), and others (n = 19). Commando procedures were referenced to a subset of double-valve replacements using balancing-score methods (109 pairs).

Results

Between balanced groups, Commando versus double-valve replacement had higher total calcium scores (median 6140 vs 2680 HU, P = .03). Hospital outcomes were similar, including operative mortality (12/11% vs 8/7.3%, P = .35) and reoperation for bleeding (9/8.3% vs 5/4.6%, P = .28). Survival and freedom from reoperation at 5 years were 54% versus 67% (P = .33) and 87% versus 100% (P = .04), respectively. Higher calcium score was associated with lower survival after double-valve replacement but not after the Commando. The Commando procedure had lower aortic valve mean gradients at 4 years (9.4 vs 11 mm Hg, P = .04). After Commando procedures for calcification, 5-year survival was 60% and 59% with and without radiation, respectively (P = .47).

Conclusions

The Commando procedure with reconstruction of the intervalvular fibrosa destroyed by mitral anular calcification, radiation, or previous surgery demonstrates acceptable outcomes similar to standard double-valve replacement. More experience and long-term outcomes are required to refine patient selection for and application of the Commando approach.

Mitral Annular Calcification-Related Valvular Disease: A Challenging Entity

Mitral valve annular calcification-related valvular disease is increasingly common due to the rising prevalence of age-related mitral annular calcifications. Mitral annular calcification alters the structure and function of the mitral valve annulus, which in turn causes mitral valve regurgitation, stenosis, or both. As it frequently coexists with comorbid conditions and overlapping symptoms, mitral annular calcification-related valvular disease poses significant diagnostic and therapeutic challenges. For instance, left ventricular diastolic dysfunction hinders the assessment of mitral valvular disease. Detection of mitral annular calcifications and assessment of related mitral valve disease hinge on two-dimensional echocardiography. Comprehensive assessment of mitral annular calcifications and related mitral valve disease may require multidetector computed tomography and three-dimensional echocardiography. Invasive hemodynamic testing with exercise helps identify the cause of symptoms in patients with comorbid conditions, and transcatheter interventions have emerged as a viable therapeutic option for older patients. After an outline of the normal mitral annulus, we examine how mitral annular calcifications lead to mitral valve disease and how to accurately assess mitral regurgitation and stenosis. Lastly, we review surgical and transcatheter approaches to the management of mitral annular calcification-related mitral valve regurgitation, stenosis, or both.

Scoring model based on cardiac CT and clinical factors to predict early good mitral valve repair in rheumatic mitral disease

OBJECTIVE

We aimed to evaluate the mitral valve calcification and mitral structure detected by cardiac computed tomography (cardiac CT) and establish a scoring model based on cardiac CT and clinical factors to predict early good mitral valve repair (EGMR) and guide surgical strategy in rheumatic mitral disease (RMD).

MATERIALS AND METHODS

This is a retrospective bi-center cohort study. Based on cardiac CT, mitral valve calcification and mitral structure in RMD were quantified and evaluated. The primary outcome was EGMR. A logical regression algorithm was applied to the scoring model.

RESULTS

A total of 579 patients were enrolled in our study from January 1, 2019, to August 31, 2022. Of these, 443 had baseline cardiac CT scans of adequate quality. The calcification quality score, calcification and thinnest part of the anterior leaflet clean zone, and papillary muscle symmetry were the independent CT factors of EGMR. Coronary artery disease and pulmonary artery pressure were the independent clinical factors of EGMR. Based on the above six factors, a scoring model was established. Sensitivity = 95% and specificity = 95% were presented with a cutoff value of 0.85 and 0.30 respectively. The area under the receiver operating characteristic of external validation set was 0.84 (95% confidence interval [CI] 0.73-0.93).

CONCLUSIONS

Mitral valve repair is recommended when the scoring model value > 0.85 and mitral valve replacement is prior when the scoring model value < 0.30. This model could assist in guiding surgical strategies for RMD.

CLINICAL RELEVANCE STATEMENT

The model established in this study can serve as a reference indicator for surgical repair in rheumatic mitral valve disease.

KEY POINTS

• Cardiac CT can reflect the mitral structure in detail, especially for valve calcification. • A model based on cardiac CT and clinical factors for predicting early good mitral valve repair was established. • The developed model can help cardiac surgeons formulate appropriate surgical strategies.

Noncontrast cardiac computed tomography-derived mitral annular calcification scores in mitral valve disease

BACKGROUND AND AIMS

Mitral annular calcification (MAC) by computed tomography (CT) is reported as an independent predictor of poor outcomes. However, it currently remains unclear if quantitative MAC parameters provide more value for mitral valve disease (MVD) management, therefore, we examined the prognostic value of MAC scores using noncontrast cardiac-CT in MVD patients.

METHODS

Between January 2020 and December 2021, we prospectively enrolled 300 consecutive patients with MVD (MAC-present = 80 and MAC-absent = 220) undergoing preoperative cardiac-CT and mitral valve (MV) surgery. Noncontrast cardiac-CT images were used to qualitatively detect MAC (present or absent) and evaluate MAC scores. For analyses, we also collected baseline clinical data, intraoperative conversion (from MV repair to MV replacement), and follow-up arrhythmia data.

RESULTS

Compared with the MAC-absent group, MAC-present patients were older (62 ± 7 vs. 58 ± 9 years, p < .001), mostly women (55% vs. 39.5%, p = .017), and also had aortic valve calcification (57.5% vs. 23.2%, p < .001), mitral stenosis (82.5% vs. 61.8%, p < .001), atrial fibrillation (30% vs. 11.8%, p < .001), and larger left atrial end-diastolic dimension (LADD, 49 [44-56] versus 46 [41-50], p = .001]. Furthermore, MAC-present patients underwent more MV replacements (61.8% vs. 82.5%, p = .001) and experienced a higher intraoperative conversion prevalence (11.8% vs. 61.3%, p < .001). Multiple logistic regression analyses showed that the female gender (odds ratio [OR]/95% confidence interval [CI]/p = 2.001/1.042-3.841/0.037) and MAC scores (OR/95% CI/p = 10.153/4.434-23.253/p < .001) were independent predictors of intraoperative conversion. During a follow-up of 263 ± 134 days, MAC-present patients had more arrhythmias (42.5% vs. 9.5%, p < .001). Also, MAC-scores (hazard ratio [HR]/95% CI/p = 6.841/3.322-14.089/p < .001) and LADD (HR/95% CI/p = 1.039/1.018-1.060/p < .001) were independently associated with arrhythmias by Cox regression analyses.

CONCLUSIONS

Noncontrast cardiac CT-derived MAC-scores showed a high risk for intraoperative conversion and follow-up arrhythmias in MVD-patients.

Implications of Renal Disease in Patients Undergoing Structural Interventions

Percutaneous structural interventions have a major impact on the morbidity, mortality, and quality of life of patients by providing a lower-risk alternative to cardiac surgery. However, renal disease has a significant impact on outcomes of these interventions. This review explores the incidence, outcomes, pathophysiology, and preventative measures of acute kidney injury and chronic kidney disease on transcatheter aortic valve replacement, transcatheter mitral valve repair, and percutaneous balloon mitral valvuloplasty. Given the expanding indications for percutaneous structural interventions, further research is needed to identify ideal patients with chronic kidney disease or end-stage renal disease who would benefit from intervention.

Diagnosis, Classification, and Management Strategies for Mitral Annular Calcification: A Heart Valve Collaboratory Position Statement

Mitral annular calcium (MAC) with severe mitral valvular dysfunction presents a complex problem, as valve replacement, either surgical or transcatheter, is challenging because of anatomy, technical considerations, concomitant comorbidities, and advanced age. The authors review the clinical and anatomical features of MAC that are favorable (green light), challenging (yellow light), or prohibitive (red light) for surgical or transcatheter mitral valve interventions. Under the auspices of the Heart Valve Collaboratory, an expert working group of cardiac surgeons, interventional cardiologists, and interventional imaging cardiologists was formed to develop recommendations regarding treatment options for patients with MAC as well as a proposed grading and staging system using both anatomical and clinical features.

Mitral annular calcification as a predictor of stroke in the multiethnic study of atherosclerosis

BACKGROUND

Mitral annular calcification (MAC) is associated with an increased risk for cardiovascular morbidity and mortality. This study provides recent data on the association between cardiac computed tomography (CT) derived MAC and 15 years of stroke risk in a racially diverse cohort.

METHODS

All multiethnic studies of atherosclerosis participants ( n  = 6814) who completed a cardiac CT at baseline were included in this analysis. MAC score was calculated from cardiac CT using the Agatston and volume score methods. Multivariable Cox proportional hazard regression models were used to compute hazard ratios for the association between MAC and stroke after adjusting for traditional cardiovascular risk factors, inflammatory markers, coronary artery calcium score, atrial fibrillation, and left atrial size.

RESULTS

Overall, 9% of participants (644/6814) had MAC at baseline. Over a surveillance period of 15 years, 304 strokes occurred, and 79% were ischemic strokes. After adjusting for age, sex, race/ethnicity, SBP, diabetes, smoking, fibrinogen, IL-6, high-sensitivity C-reactive protein, and coronary artery calcium score, baseline MAC was associated with increased risk for all strokes [hazard ratio 1.68; 95% confidence interval (CI) 1.22-2.30: P  = 0.0013]. When atrial fibrillation/flutter and left atrial size were included in the final multivariable model, MAC remained a predictor of all strokes (hazard ratio 1.93; 95% CI 1.22-3.05: P  < 0.0051) and ischemic stroke (hazard ratio 2.03; 95% CI 1.24-3.31: P  < 0.0046).

CONCLUSION

MAC is an independent predictor of long-term stroke risk in a racially diverse population beyond conventional cardiovascular risk factors and atrial fibrillation.

Latent Coronary Plaque Morphology From Computed Tomography Angiography, Molecular Disease Activity on Positron Emission Tomography, and Clinical Outcomes

BACKGROUND

Assessments of coronary disease activity with 18F-sodium fluoride positron emission tomography and radiomics-based precision coronary plaque phenotyping derived from coronary computed tomography angiography may enhance risk stratification in patients with coronary artery disease. We sought to investigate whether the prognostic information provided by these 2 approaches is complementary in the prediction of myocardial infarction.

METHODS

Patients with known coronary artery disease underwent coronary 18F-sodium fluoride positron emission tomography and coronary computed tomography angiography on a hybrid positron emission tomography/computed tomography scanner. Coronary 18F-NaF uptake was determined by the coronary microcalcification activity. We performed quantitative plaque analysis of coronary computed tomography angiography datasets and extracted 1103 radiomic features for each plaque. Using weighted correlation network analysis, we derived latent morphological features of coronary lesions which were aggregated to patient-level radiomics nomograms to predict myocardial infarction.

RESULTS

Among 260 patients with established coronary artery disease (age, 65±9 years; 83% men), 179 (69%) participants showed increased coronary 18F-NaF activity (coronary microcalcification activity>0). Over 53 (40-59) months of follow-up, 18 patients had a myocardial infarction. Using weighted correlation network analysis, we derived 15 distinct eigen radiomic features representing latent morphological coronary plaque patterns in an unsupervised fashion. Following adjustments for calcified, noncalcified, and low-density noncalcified plaque volumes and 18F-NaF coronary microcalcification activity, 4 radiomic features remained independent predictors of myocardial infarction (hazard ratio, 1.46 [95% CI, 1.03-2.08]; P=0.03; hazard ratio, 1.62 [95% CI, 1.04-2.54]; P=0.02; hazard ratio, 1.49 [95% CI, 1.07-2.06]; P=0.01; and hazard ratio, 1.50 (95% CI, 1.05-2.13); P=0.02).

CONCLUSIONS

In patients with established coronary artery disease, latent coronary plaque morphological features, quantitative plaque volumes, and disease activity on 18F-sodium fluoride positron emission tomography are additive predictors of myocardial infarction.

Transcatheter Mitral Valve Replacement in Patients with Mitral Annular Calcification: A Review

Mitral annular calcification (MAC) is a progressive degenerative calcification of the mitral valve (MV) that is associated with mitral stenosis, regurgitation or both. Patients with MAC are poor candidates for MV surgery because of technical challenges and high peri-operative mortality. Transcatheter MV replacement (TMVR) has emerged as an option for such high surgical risk patients. This has been described with the use of the SAPIEN transcatheter heart valve (valve-in-MAC) and dedicated TMVR devices. Careful anatomic assessment is important to avoid complications of TMVR, such as left ventricular outflow tract obstruction, valve migration, embolization and paravalvular mitral regurgitation. In this review, we discuss the pathology, importance of preprocedural multimodality imaging for optimal patient selection, clinical outcomes and complications associated with TMVR in patients with MAC.

Mitral Annular Calcification Related Infective Endocarditis: A Contemporary Systematic Review

Mitral annular calcification (MAC) is a chronic degenerative process often found incidentally on imaging. MAC is associated with elevated risk of atherosclerosis and stroke. The association between MAC and the risk of infective endocarditis (IE) is less well known. Therefore, we conducted this systematic review in order to understand the diagnosis, clinical outcomes, and management of IE associated with MAC. We conducted a systematic review of published data regarding MAC related IE in various databases until November 20, 2019. Case series and cohort studies were included. A total of 8 studies with a cohort of 113 patients were included. Mean age was 69 years with equal gender distribution (50% female). Hypertension (55.8%) was the most common comorbidity seen in this patient population. IE was diagnosed by either antemortem trans esophageal echocardiographic examination (76%) or post-mortem autopsy (24%). Staphylococcus aureus (47%) was the most common pathogen identified. MAC was adjudicated to be moderate-to-severe in 100% of identified cases, with 77.9% of cases presenting with distinct vegetation's. Twenty-six percent of patients (n = 29) underwent surgery. MAC may be associated with development of IE. Echocardiography is the most common non-invasive technique for diagnosis. Due to the difficulties associated with antemortem diagnosis, diagnosis is occasionally made on post-mortem examination. Neurologic complications are frequently encountered, and reported mortality is high in MAC associated IE.

18F-Sodium Fluoride PET/CT in Assessing Valvular Heart and Atherosclerotic Diseases

Aortic valve stenosis is the most common valvular disease in Western countries, while atherosclerotic cardiovascular disease is the foremost cause of death and disability worldwide. Valve degeneration and atherosclerosis are mediated by inflammation and calcification and inevitably progress over time. Computed tomography can visualise the later stages of macroscopic calcification but fails to assess the early stages of microcalcification and cannot differentiate active from burnt out disease states. Molecular imaging has the ability to provide complementary information related to disease activity, which may allow us to detect disease early, to predict disease progression and to monitor preventive or therapeutic strategies for in both aortic stenosis and atherosclerosis. PET/CT is a non-invasive imaging technique that enables visualization of ongoing molecular processes within small structures, such as the coronary arteries or heart valves. ¹⁸F-sodium fluoride (¹⁸F-NaF) binds hydroxyapatite deposits in the extracellular matrix, with preferential binding to newly developing deposits of microcalcification, which provides an assessment of calcification activity. In recent years, ¹⁸F-NaF has attracted the attention of many research groups and has been evaluated in several pathological cardiovascular processes. Histologic validation of the ¹⁸F-NaF PET signal in valvular disease and atherosclerosis has been reported in multiple independent studies. The selective high-affinity binding of ¹⁸F-NaF to microscopic calcified deposits (beyond the resolution of μCT) has been demonstrated ex vivo, as well as its ability to distinguish between areas of macro- and active microcalcification. In addition, prospective clinical studies have shown that baseline ¹⁸F-NaF uptake in patients with aortic stenosis and mitral annular calcification is correlated with subsequent calcium deposition and valvular dysfunction after a follow-up period of 2 years. In patients with surgical bioprosthetic aortic valves but without morphological criteria for prosthetic degeneration, increased ¹⁸F-NaF uptake at baseline was associated with subsequent bioprosthetic degeneration over time. Similar data were obtained in a cohort of patients with transcatheter aortic valve implantation. Furthermore, several studies have confirmed the association of coronary ¹⁸F-NaF uptake with adverse atherosclerotic plaque features, active disease and future disease progression. ¹⁸F-NaF uptake is also associated with future fatal or nonfatal myocardial infarction in patients with established coronary artery disease. The link between ¹⁸F-NaF uptake and active atherosclerotic disease has not only been demonstrated in the coronary arteries, but also in peripheral arterial disease, abdominal aortic aneurysms and carotid atherosclerosis. It can be assumed that ¹⁸F-NaF PET/CT will strengthen the diagnostic toolbox of practitioners in the coming years. Indeed, there is a strong medical need to diagnose degenerative valvular disease and to detect active atherosclerotic disease states. Finally, the use of ¹⁸F-NaF as a biomarker to monitor the efficacy of drug therapies in preventing these pathological processes is attractive. In this review, we consider the role of ¹⁸F-NaF PET/CT imaging in cardiac valvular diseases and atherosclerosis.

Atherogenic index of plasma is an independent predictor of mitral annular calcification

BACKGROUND

In the latest reports, atherogenic indices have been related to acute coronary syndromes, stable coronary artery disease, heart failure and future cardiac events. Conventional atherosclerosis risk factors have been associated with mitral annular calcification (MAC), but data on the relationship between atherogenic indices and MAC are lacking. We aimed to investigate a possible relationship between MAC and atherogenic indices.

METHODS

In total 741 patients (n = 427 with MAC and n = 314 without MAC) who were examined in our cardiology clinic from February 2016 to October 2021 were recruited in the study. Mitral annular calcification was diagnosed by transthoracic 2-dimensional echocardiography. The atherogenic coefficient (AC), Castelli risk index 1 (CRI-1), Castelli risk index 2 (CRI-2) and atherogenic index of plasma (AIP) were calculated by utilizing standard lipid test values.

RESULTS

There was no statistically significant difference in sex, age, diabetes and hypertension status between the patient and the control groups. Serum triglyceride level, AIP, Hs-CRP, smoking and BMI were independently significantly associated with MAC in multiple regression analysis (p < 0.001).

CONCLUSION

Higher AIP was related to the existence of MAC and also predict the presence of MAC independently. Studies evaluating the modification of these indices are needed.

Mitral Valve Dysfunction in Patients With Annular Calcification: JACC Review Topic of the Week

Mitral annular calcification (MAC) is a common clinical finding and is associated with adverse clinical outcomes, but the clinical impact of MAC-related mitral valve (MV) dysfunction remains underappreciated. Patients with MAC frequently have stenotic, regurgitant, or mixed valvular disease, and this valvular dysfunction is increasingly recognized to be independently associated with worse prognosis. MAC-related MV dysfunction is a distinct pathophysiologic entity, and importantly much of the diagnostic and therapeutic paradigm from published rheumatic MV disease research cannot be applied in this context, leaving important gaps in our knowledge. This review summarizes the current epidemiology, pathophysiology, diagnosis, and classification of MAC-related MV dysfunction and proposes both an integrative definition and an overarching approach to this important and increasingly recognized clinical condition.

Cardiac microcalcification burden: Global assessment in high cardiovascular risk subjects with Na[18F]F PET-CT

BACKGROUND

Fluorine-18 sodium fluoride (Na[18F]F) atherosclerotic plaque uptake in positron emission tomography with computed tomography (PET-CT) identifies active microcalcification. We aim to evaluate global cardiac microcalcification activity with Na[18F]F, as a measure of unstable microcalcification burden, in high cardiovascular (CV) risk patients.

METHODS AND RESULTS

Thirty-four high CV risk individuals without previous CV events were scanned with Na[18F]F PET-CT. Cardiac Na[18F]F uptake was assessed through the global molecular calcium score (GMCS), which was calculated by summing the product of the mean standardized uptake value times the area of the cardiac regions of interest times the slice thickness for all cardiac transaxial slices, divided by the total number of slices. Mean age is 63.5 ± 7.8 years and 62% male. Median GMCS is 320.9 (240.8-402.8). Individuals with more than five CV risk factors (50%) have increased GMCS [356.7 (321.0-409.6) vs. 261.1 (225.6-342.1), P = 0.01], which is positively correlated with predicted fatal CV risk by SCORE (rs = 0.32, P = 0.04). There is a positive correlation between GMCS and weight (rs = 0.61), body mass index (rs = 0.66), abdominal perimeter (rs = 0.74), thoracic fat volume (rs = 0.47), and epicardial adipose tissue (rs = 0.41), all with P ≤ 0.01. There is no correlation between GMCS and coronary calcium score nor coronary artery wall Na[18F]F uptake.

CONCLUSIONS

In a high CV risk group, the global cardiac microcalcification burden is related to CV risk factors, metabolic syndrome variables and cardiac fat. Cardiac GMCS is a promising risk stratification tool, combining a straightforward and objective methodology with a comprehensive analysis of both coronary and valvular microcalcification.

Prognostic value of left atrial volume index in degenerative mitral stenosis

Purpose

Degenerative mitral stenosis (DMS) is associated with a poor prognosis. Although mean transmitral gradient (TMG) has shown a good correlation with outcome, little is known about the association between other echocardiographic parameters and prognosis in patients with DMS. The current study aimed to evaluate the prognostic value of left atrial volume index (LAVI) in patients with DMS.

Methods

A total of 155 patients with DMS (72[63–80] years, 67% female) were included. The population was divided according to LAVI: normal-sized LAVI (LAVI ≤ 34 ml/m2); and enlarged LAVI (> 34 ml/m2).

Results

Patients with enlarged LAVI had a higher left ventricular mass index (120[96–146] vs. 91[70–112] g/m2 p < 0.001), as well as a higher prevalence of significant mitral regurgitation and severe aortic stenosis (23% vs. 10% p = 0.046 and 38% vs. 15% p=0.001, respectively) compared to patients with normal-sized LAVI. During a median follow-up of 25 months, 56 (36%) patients died. Patients with enlarged LAVI had worse prognosis compared to patients with normal-sized LAVI (p = 0.026). In multivariable Cox regression model, an enlarged LAVI was independently associated with all-cause mortality (HR 2.009, 95% CI 1.040 to 3.880, P = 0.038).

Conclusion

An enlarged LAVI (> 34 ml/m2) is significantly associated with excess mortality in patients with DMS. After adjusting for potential confounders, an enlarged LAVI was the only parameter that remained independently associated with prognosis.

Radiotracers to Address Unmet Clinical Needs in Cardiovascular Imaging, Part 2: Inflammation, Fibrosis, Thrombosis, Calcification, and Amyloidosis Imaging

Cardiovascular imaging is evolving in response to systemwide trends toward molecular characterization and personalized therapies. The development of new radiotracers for PET and SPECT imaging is central to addressing the numerous unmet diagnostic needs that relate to these changes. In this 2-part review, we discuss select radiotracers that may help address key unmet clinical diagnostic needs in cardiovascular medicine. Part 1 examined key technical considerations pertaining to cardiovascular radiotracer development and reviewed emerging radiotracers for perfusion and neuronal imaging. Part 2 covers radiotracers for imaging cardiovascular inflammation, thrombosis, fibrosis, calcification, and amyloidosis. These radiotracers have the potential to address several unmet needs related to the risk stratification of atheroma, detection of thrombi, and the diagnosis, characterization, and risk stratification of cardiomyopathies. In the first section, we discuss radiotracers targeting various aspects of inflammatory responses in pathologies such as myocardial infarction, myocarditis, sarcoidosis, atherosclerosis, and vasculitis. In a subsequent section, we discuss radiotracers for the detection of systemic and device-related thrombi, such as those targeting fibrin (e.g., ⁶⁴Cu-labeled fibrin-binding probe 8). We also cover emerging radiotracers for the imaging of cardiovascular fibrosis, such as those targeting fibroblast activation protein (e.g., ⁶⁸Ga-fibroblast activation protein inhibitor). Lastly, we briefly review radiotracers for imaging of cardiovascular calcification (¹⁸F-NaF) and amyloidosis (e.g., ^99mTc-pyrophosphate and ¹⁸F-florbetapir).

Extracorporeal Membrane Oxygenation-Supported Transcatheter Mitral Valve-in-Valve Replacement and Paravalvular Plugging for Critical Prosthetic Mitral Stenosis

We present the case of a patient with rapidly progressive bioprosthetic mitral valve stenosis in the setting of end-stage renal failure. Critical valve stenosis led to cardiogenic shock requiring full hemodynamic support. Emergent extracorporeal membrane oxygenation–supported transcatheter mitral valve-in-valve implantation was successfully undertaken as a life-saving measure with an excellent final result. (Level of Difficulty: Advanced.)

Observer repeatability and interscan reproducibility of 18F-sodium fluoride coronary microcalcification activity

BACKGROUND

We aimed to establish the observer repeatability and interscan reproducibility of coronary 18F-sodium-fluoride positron emission tomography (PET) uptake using a novel semi-automated approach, coronary microcalcification activity (CMA).

METHODS

Patients with multivessel coronary artery disease underwent repeated hybrid PET and computed tomography angiography (CTA) imaging (PET/CTA). CMA was defined as the integrated standardized uptake values (SUV) in the entire coronary tree exceeding 2 standard deviations above the background SUV. Coefficients of repeatability between the same observer (intraobserver repeatability), between 2 observers (interobserver repeatability) and coefficient of reproducibility between 2 scans (interscan reproducibility), were determined at vessel and patient level.

RESULTS

In 19 patients, CMA was assessed twice in 43 coronary vessels on two PET/CT scans performed 12 ± 5 days apart. There was excellent intraclass correlation for intraobserver and interobserver repeatability as well as interscan reproducibility (all ≥ 0.991). There was 100% intraobserver, interobserver and interscan agreement for the presence (CMA > 0) or absence (CMA = 0) of coronary18F-NaF uptake. Mean CMA was 3.12 ± 0.62 with coefficients of repeatability of ≤ 10% for all measures: intraobserver 0.24 and 0.22, interobserver 0.30 and 0.29 and interscan 0.33 and 0.32 at a per-vessel and per-patient level, respectively.

CONCLUSIONS

CMA is a repeatable and reproducible global measure of coronary atherosclerotic activity.

Hybrid Surgery for Severe Mitral Valve Calcification: Limitations and Caveats for an Open Transcatheter Approach

Background and Objectives: Mitral stenosis with extensive mitral annular calcification (MAC) remains surgically challenging in respect to clinical outcome. Prolonged surgery time with imminent ventricular rupture and systolic anterior motion can be considered as a complex of causal factors. The aim of our alternative hybrid approach was to reduce the risk of annual rupture and paravalvular leaks and to avoid obstruction of the outflow tract. A review of the current literature was also carried out. Materials and Methods: Six female patients (mean age 76 ± 9 years) with severe mitral valve stenosis and severely calcified annulus underwent an open implantation of an Edwards Sapien 3 prosthesis on cardiopulmonary bypass. Our hybrid approach involved resection of the anterior mitral leaflet, placement of anchor sutures and the deployment of a balloon expanded prosthesis under visual control. Concomitant procedures were carried out in three patients. Results: The mean duration of cross-clamping was 95 ± 31 min and cardiopulmonary bypass was 137 ± 60 min. The perioperative TEE showed in three patients an inconspicuous, heart valve-typical gradient on all implanted prostheses and a clinically irrelevant paravalvular leakage occurred in the anterior annulus. In the left ventricular outflow tract, mild to moderately elevated gradients were recorded. No adverse cerebrovascular events and pacemaker implantations were observed. All but one patient survived to discharge. Survival at one year was 83.3%. Conclusions: This “off label” implantation of the Edwards Sapien 3 prosthesis may be considered as a suitable bail-out approach for patients at high-risk for mitral valve surgery or deemed inoperable due to extensive MAC.

Purposeful use of multimodality imaging in the diagnosis of caseous mitral annular calcification: a case series report

BACKGROUND

Caseous mitral annular calcification (CMAC) is a rare liquefactive variant of mitral annular calcification (MAC) and superficially mimics a cardiac vegetation or abscess. CMAC is viewed as a benign condition of MAC, while MAC has clinical implications for patients' lives. Correctly diagnosing CMAC is essential in order to avoid unnecessary interventions, cardiac surgery or even psychological suffering for the patient.

CASE PRESENTATION

We report on 6 patients with suspected intra-cardiac masses of the mitral annulus that were referred to our institution for further clarification. A definitive diagnosis of CMAC was achieved by combining echocardiography (Echo), cardiac magnetic resonance imaging (MRI) and cardiac computed tomography (CT) for these patients. Echo assessed the mass itself and possible interactions with the mitral valve. MRI was useful in differentiating the tissue from other benign or malign neoplasms. CT revealed the typical structure of CMAC with a "soft" liquefied centre and an outer capsule with calcification.

CONCLUSION

CMAC is a rare condition, and most clinicians and even radiologists are not familiar with it. CMAC can be mistaken for an intra-cardiac tumour, thombus, vegetation, or abscess. Non-invasive multimodality imaging (i.e. Echo, MRI, and CT) helps to establish a definitive diagnosis of CMAC and avoid unnecessary interventions especially in uncertain cases.

Mitral annular calcification in hypertrophic cardiomyopathy

BACKGROUND

Changes in mitral valve anatomy contribute to left ventricular outflow tract obstruction (LVOTO) in hypertrophic cardiomyopathy (HCM). Mitral annular calcification (MAC) is common among patients with HCM but its implications are currently unknown.

METHODS

We tested the hypothesis that echocardiographic MAC would be associated with anterior displacement of the mitral valve and LVOTO in a cohort of 304 patients with HCM aged ≥ 60 years (mean [SD] age 71.6 [7.7] years, 52% women).

RESULTS

MAC was present in 141 (46%) patients. The mean (SD) MAC offset distance was 9.8 (4.8) mm. A higher proportion of those with MAC compared to those without MAC had SAM (84.2 vs. 63.8%, p < 0.001) and LVOTO (80.9 vs. 57.9%, p < 0.001). In patients with MAC, the septal-mitral valve distance was shorter compared to those without (19.4 [4.0] vs 21.5 [4.9] mm, p < 0.001). The mitral valve position ratio was greater in those with MAC compared to those without (1.00 [0.79, 1.22] vs. 0.86 [0.67, 1.05], p < 0.001) denoting greater anterior displacement, especially in those with MAC and LVOTO. After multivariable adjustment, MAC offset distance was associated with LVOTO (OR 1.16 [95% CI 1.07, 1.28] per mm, p = 0.001). Over a median follow-up of 2.7 years, 42 (29.8%) patients with MAC underwent surgery to relieve LVOTO, with no deaths.

CONCLUSION

This study adds MAC to the known geometrical alterations of the mitral valve that predispose to LVOTO and suggests that surgical relief of LVOTO in the presence of MAC is safe when performed by an experienced surgeon.

Sex Differences in Mitral Annular Calcification and the Clinical Implications

Background: Heterogeneous mechanisms may contribute to the occurrence of mitral annular calcification (MAC), however, little is known about the sex differences in MAC and the clinical implications of these differences. This study aimed to investigate clinical and imaging differences of MAC according to sex.

Methods: In total, 537 patients (221 men) with MAC were identified by transthoracic echocardiography at a single center from January 2012 to June 2016. Moderate-to-severe MAC was defined as calcification extent ≥120° of the mitral annulus. Significant functional mitral stenosis (MS) was defined as a transmitral mean diastolic pressure gradient ≥5 mmHg.

Results: Women more frequently had moderate-to-severe MAC and concomitant mitral regurgitation than men; however, significant functional MS was comparable between sexes. In the logistic regression analysis, old age, uncontrolled hypertension, end-stage renal disease (ESRD), and obstructive hypertrophic cardiomyopathy were significantly associated with moderate-to-severe MAC in women, whereas ESRD and moderate-to-severe aortic stenosis were in men. In the Cox regression analysis, significant functional MS was associated with all-cause death in both sexes, although an independent association was found in only women.

Conclusion: Women had more extended MAC than men. Significant functional MS was independently associated with unfavorable clinical outcomes in patients with MAC, which was more pronounced in women than in men.

Transcatheter mitral valve replacement for degenerated mitral valve bioprostheses, failure of mitral valvuloplasty and native valve with severe mitral annulus calcification: a systematic review and meta-analysis

Background

Although transcatheter technology has achieved some success in the field of mitral valves, the feasibility of applying it to patients with degenerated mitral valve bioprostheses (valve-in-valve, ViV), failure of mitral valvuloplasty (valve-in-ring, ViR) and serious mitral annulus calcification (vale-in-MAC, ViMAC) has not been effectively evaluated.

Methods

By searching published literature before December 5, 2020 in four databases, we found all the literature related to the evaluation of feasibility assessment of TMViV, TMViR and TMViMAC. Outcomes focused on all-cause mortality within 30 days, bleeding and LVOT obstruction.

Results

A total of six studies were included, and all of them were followed up for at least 30 days. After analysis of the ViV–ViR group, we obtained the following results: the all-cause mortality within 30 days of the ViV group was lower than that of the ViR group. Life-threatening or fatal bleeding was more likely to occur in the ViR group after surgery. At the same time, the ViR group was more prone to left ventricular outflow tract obstruction. However, in the ViMAC–ViR group, only the all-cause mortality within 30 days and stroke were statistically significant. In the indirect comparison, we found that TMViV had the best applicability, followed by TMViR. There were few TMViMAC available for analysis, and it requires further studies to improve the accuracy of the results.

Conclusion

TMViV and TMViR had good applicability and could benefit patients who underwent repeat valve surgery. The feasibility of TMViMAC needs to be further explored and improved.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01677-7.

Iterative reconstruction incorporating background correction improves quantification of [18F]-NaF PET/CT images of patients with abdominal aortic aneurysm

BACKGROUND

A confounding issue in [18F]-NaF PET/CT imaging of abdominal aortic aneurysms (AAA) is the spill in contamination from the bone into the aneurysm. This study investigates and corrects for this spill in contamination using the background correction (BC) technique without the need to manually exclude the part of the AAA region close to the bone.

METHODS

Seventy-two (72) datasets of patients with AAA were reconstructed with the standard ordered subset expectation maximization (OSEM) algorithm incorporating point spread function (PSF) modelling. The spill in effect in the aneurysm was investigated using two target regions of interest (ROIs): one covering the entire aneurysm (AAA), and the other covering the aneurysm but excluding the part close to the bone (AAAexc). ROI analysis was performed by comparing the maximum SUV in the target ROI (SUVmax(T)), the corrected cSUVmax (SUVmax(T) - SUVmean(B)) and the target-to-blood ratio (TBR = SUVmax(T)/SUVmean(B)) with respect to the mean SUV in the right atrium region.

RESULTS

There is a statistically significant higher [18F]-NaF uptake in the aneurysm than normal aorta and this is not correlated with the aneurysm size. There is also a significant difference in aneurysm uptake for OSEM and OSEM + PSF (but not OSEM + PSF + BC) when quantifying with AAA and AAAexc due to the spill in from the bone. This spill in effect depends on proximity of the aneurysms to the bone as close aneurysms suffer more from spill in than farther ones.

CONCLUSION

The background correction (OSEM + PSF + BC) technique provided more robust AAA quantitative assessments regardless of the AAA ROI delineation method, and thus it can be considered as an effective spill in correction method for [18F]-NaF AAA studies.

Bone mineral density and long-term progression of aortic valve and mitral annular calcification: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

Bone and mineral metabolism has been implicated in the pathophysiology of cardiac valve calcification. Whether bone demineralization, a common aging-related disorder, promotes calcific valve disease remains uncertain. We tested the hypothesis that low bone mineral density (BMD) is associated with greater incidence/progression of cardiac valve calcification in the Multi-Ethnic Study of Atherosclerosis.

METHODS

Using linear mixed-effects models, we related baseline measurement of BMD of the thoracic vertebrae by computed tomography (CT) in 6768 participants to serial CT assessments of aortic valve calcification (AVC) and mitral annular calcification (MAC) obtained over a >10-year period.

RESULTS

After multivariable adjustment, lower BMD (per SD decrement) was associated with accelerated increase in AVC over time in women (0.76 [95% CI 0.42,1.09] Agatston -units [AU]/year) and men (1.41 [95% CI 0.48,2.33] AU/year), as well as for MAC in women (3.22 [95% CI 1.16,5.28] AU/year) and men (3.59 [95% CI 2.09,5.09] AU/year). Significant effect modification was observed, with more pronounced BMD-related acceleration of AVC and MAC progression in older or white participants of one or both sexes, as well as by estimated glomerular filtration rate, though the latter differed by sex for AVC and MAC.

CONCLUSIONS

In this multi-ethnic cohort, low thoracic BMD was significantly, but modestly, associated with increased AVC and MAC progression. This suggests that altered bone mineral metabolism does not have a major impact on calcific valve disease in the general population, but the possibility of a more meaningful influence in higher-risk individuals with osteoporosis will require further investigation.

Mitral annular calcification and valvular dysfunction: multimodality imaging evaluation, grading, and management

Mitral annular calcification (MAC) refers to calcium deposition in the fibrous skeleton of the mitral valve. It has many cardiovascular associations, including mitral valve dysfunction, elevated cardiovascular risk, arrhythmias, and endocarditis. Echocardiography conventionally is the first-line imaging modality for anatomic assessment, and evaluation of mitral valve function. Cardiac computed tomography (CT) has demonstrated importance as an imaging modality for the evaluation and planning of related procedures. It also holds promise in quantitative grading of MAC. Currently, there is no universally accepted definition or classification system of MAC severity. We review the multimodality imaging evaluation of MAC and associated valvular dysfunction and propose a novel classification system based on qualitative and quantitative measurements derived from echocardiography and cardiac CT.

How to Manage Mitral Stenosis Due to Mitral Annular Calcification

PURPOSE OF REVIEW

Mitral annular calcification (MAC) is associated with cardiovascular comorbidities and events and in the presence of mitral stenosis (MS) represents a high-risk cohort with limited treatment options. Emerging hybrid, minimally invasive, and transcatheter therapies that use circumferential MAC as an anchor for mitral valve replacement are emerging, but none are consistently associated with ideal outcomes.

RECENT FINDINGS

In patients with MAC and nonrheumatic calcific mitral stenosis who are severely symptomatic, mitral intervention may be indicated. Surgical decalcification and replacement of the mitral valve remains the conventional therapy. Surgical techniques to avoid decalcification are being described including a left atrium to left ventricular apex graft conduit. Transcatheter balloon-expandable valves designed for the aortic valve have been implanted in the mitral position in MAC with a surgical direct transatrial transcatheter approach or transseptal transcatheter approach. Left ventricular outflow tract (LVOT) obstruction remains prevalent and associated with increased mortality. Direct transatrial approach allows for surgical resection of the anterior leaflet to mitigate this risk, and percutaneous therapies to lacerate the anterior leaflet or to ablate the basal septum are being developed. Cardiac computed tomography has emerged as a requisite for patient selection and procedural planning and has powerful predictive value for LVOT obstruction and valve embolization in valve-in-MAC. Novel transcatheter valves designed specifically for the mitral space are being studied in patients with MAC. MAC with mitral stenosis remains a challenging disease. Advances in technique, technology, and imaging may create new and reproducible treatment options with low procedural mortality for this challenging disease entity.

Current methods to assess mitral annular calcification and its risk factors

INTRODUCTION

Mitral annulus calcification (MAC) is a chronic, non-inflammatory, degenerative mechanism of the fibrous base of the mitral valve. While MAC was originally thought to be an age-related degenerative process, there is evidence that other mechanisms, such as atherosclerosis and abnormal calcium phosphorus metabolism, also contribute to the development of MAC.

AREAS COVERED

This paper summarizes, existing perception of clinically valid definition of MAC and the pathophysiological processes that lead to the development of MAC and the diagnostic implications of this disease entity.

EXPERT OPINION

Minimal evidence exists on the natural history and progression of MAC. Characterization of MAC progression and identification of predisposing risk factors can help to validate hypotheses. MAC is most commonly asymptomatic and incidental finding. Echocardiography is the primary imaging modality for identification and characterization of MAC and associated mitral valve (MV) disease. For patients with an indication for MV surgery, computed tomography (CT) is a complementary imaging modality for MAC. MAC is generally recognized by its characteristic density, location, and shape on echocardiography and CT, unusual variants are sometimes confused with other lesions.

EACVI recommendations on cardiovascular imaging for the detection of embolic sources: endorsed by the Canadian Society of Echocardiography

Cardioaortic embolism to the brain accounts for approximately 15-30% of ischaemic strokes and is often referred to as 'cardioembolic stroke'. One-quarter of patients have more than one cardiac source of embolism and 15% have significant cerebrovascular atherosclerosis. After a careful work-up, up to 30% of ischaemic strokes remain 'cryptogenic', recently redefined as 'embolic strokes of undetermined source'. The diagnosis of cardioembolic stroke remains difficult because a potential cardiac source of embolism does not establish the stroke mechanism. The role of cardiac imaging-transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE), cardiac computed tomography (CT), and magnetic resonance imaging (MRI)-in the diagnosis of potential cardiac sources of embolism, and for therapeutic guidance, is reviewed in these recommendations. Contrast TTE/TOE is highly accurate for detecting left atrial appendage thrombosis in patients with atrial fibrillation, valvular and prosthesis vegetations and thrombosis, aortic arch atheroma, patent foramen ovale, atrial septal defect, and intracardiac tumours. Both CT and MRI are highly accurate for detecting cavity thrombosis, intracardiac tumours, and valvular prosthesis thrombosis. Thus, CT and cardiac magnetic resonance should be considered in addition to TTE and TOE in the detection of a cardiac source of embolism. We propose a diagnostic algorithm where vascular imaging and contrast TTE/TOE are considered the first-line tool in the search for a cardiac source of embolism. CT and MRI are considered as alternative and complementary tools, and their indications are described on a case-by-case approach.

Survival of people with valvular heart disease in a large, English community-based cohort study

OBJECTIVE

Valvular heart disease (VHD) is present in half the population aged >65 years but is usually mild and of uncertain importance. We investigated the association between VHD and its phenotypes with all-cause and cause-specific mortality.

METHODS

The OxVALVE (Oxford Valvular Heart Disease) population cohort study screened 4009 participants aged >65 years to establish the presence and severity of VHD. We linked data to a national mortality registry and undertook detailed outcome analysis.

RESULTS

Mortality data were available for 3511 participants, of whom 361 (10.3%) died (median 6.49 years follow-up). Most had some form of valve abnormality (n=2645, 70.2%). In adjusted analyses, neither mild VHD (prevalence 44.9%) nor clinically significant VHD (moderate or severe stenosis or regurgitation; 5.2%) was associated with increased all-cause mortality (HR 1.20, 95% CI 0.96 to 1.51 and HR 1.47, 95% CI 0.94 to 2.31, respectively). Conversely, advanced aortic sclerosis (prevalence 2.25%) and advanced mitral annular calcification (MAC, 1.31%) were associated with an increased risk of death (HR 2.05, 95% CI 1.28 to 3.30 and HR 2.51, 95% CI 1.41 to 4.49, respectively). Mortality was highest for people with both clinically significant VHD and advanced aortic sclerosis or MAC (HR 4.38, 95% CI 1.99 to 9.67).

CONCLUSIONS

Advanced aortic sclerosis or MAC is associated with a worse outcome, particularly for patients with significant VHD, but also in the absence of other VHD. Older patients with mild VHD can be reassured about their prognosis. The absence of an association between significant VHD and mortality may reflect its relatively low prevalence in our cohort.

Valvular calcification and risk of peripheral artery disease: the Multi-Ethnic Study of Atherosclerosis (MESA)

AIMS

The detection of cardiac valvular calcification on routine imaging may provide an opportunity to identify individuals at increased risk for peripheral artery disease (PAD). We investigated the associations of aortic valvular calcification (AVC) and mitral annular calcification (MAC) with risk of developing clinical PAD or a low ankle-brachial index (ABI).

METHODS AND RESULTS

AVC and MAC were measured on cardiac computed tomography in 6778 Multi-Ethnic Study of Atherosclerosis participants without baseline PAD between 2000 and 2002. Clinical PAD was ascertained through 2015. Incident low ABI, defined as ABI <0.9 and decline of ≥0.15, was assessed among 5762 individuals who had an ABI >0.9 at baseline and at least one follow-up ABI measurement 3-10 years later. Adjusted Cox proportional hazards and Poisson regression modelling were used to determine the association of valvular calcification with clinical PAD and low ABI, respectively. There were 117 clinical PAD and 198 low ABI events that occurred over a median follow-up of 14 years and 9.2 years, respectively. The presence of MAC was associated with an increased risk of clinical PAD [hazard ratio 1.79; 95% confidence interval (CI) 1.04-3.05] but not a low ABI (rate ratio 1.28; 95% CI 0.75-2.19). No significant associations were noted for the presence of AVC and risk of either clinical PAD.

CONCLUSION

MAC is associated with an increased risk of developing clinical PAD. Future studies are needed to corroborate our findings and better understand whether MAC holds any predictive value as a risk marker for PAD.

Multimodality imaging in valvular heart disease: how to use state-of-the-art technology in daily practice

Our understanding of the complexities of valvular heart disease (VHD) has evolved in recent years, primarily because of the increased use of multimodality imaging (MMI). Whilst echocardiography remains the primary imaging technique, the contemporary evaluation of patients with VHD requires comprehensive analysis of the mechanism of valvular dysfunction, accurate quantification of severity, and active exclusion extravalvular consequences. Furthermore, advances in surgical and percutaneous therapies have driven the need for meticulous multimodality imaging to aid in patient and procedural selection. Fundamental decision-making regarding whom, when, and how to treat patients with VHD has become more complex. There has been rapid technological advancement in MMI; many techniques are now available in routine clinical practice, and their integration into has the potential to truly individualize management strategies. This review provides an overview of the current evidence for the use of MMI in VHD, and how various techniques within each modality can be used practically to answer clinical conundrums.

The year in cardiology: imaging

Collapse

Detecting native and bioprosthetic aortic valve disease using 18F-sodium fluoride: Clinical implications

Calcific aortic valve disease is the most common valvular disease and confers significant morbidity and mortality. There are currently no medical therapies that successfully halt or reverse the disease progression, making surgical replacement the only treatment currently available. The majority of patients will receive a bioprosthetic valve, which themselves are prone to degeneration and may also need replaced, adding to the already substantial healthcare burden of aortic stenosis. Echocardiography and computed tomography can identify late-stage manifestations of the disease process affecting native and bioprosthetic aortic valves but cannot detect or quantify early molecular changes. 18F-fluoride positron emission tomography, on the other hand, can non-invasively and sensitively assess disease activity in the valves. The current review outlines the pivotal role this novel molecular imaging technique has played in improving our understanding of native and bioprosthetic aortic valve disease, as well as providing insights into its feasibility as an important future research and clinical tool.

Prevalence and clinical implications of valvular calcification on coronary computed tomography angiography

AIMS

Valvular heart disease can be identified by calcification on coronary computed tomography angiography (CCTA) and has been associated with adverse clinical outcomes. We assessed aortic and mitral valve calcification in patients presenting with stable chest pain and their association with cardiovascular risk factors, coronary artery disease, and cardiovascular outcomes.

METHODS AND RESULTS

In 1769 patients (58 ± 9 years, 56% male) undergoing CCTA for stable chest pain, aortic and mitral valve calcification were quantified using Agatston score. Aortic valve calcification was present in 241 (14%) and mitral calcification in 64 (4%). Independent predictors of aortic valve calcification were age, male sex, hypertension, diabetes mellitus, and cerebrovascular disease, whereas the only predictor of mitral valve calcification was age. Patients with aortic and mitral valve calcification had higher coronary artery calcium scores and more obstructive coronary artery disease. The composite endpoint of cardiovascular mortality, non-fatal myocardial infarction, or non-fatal stroke was higher in those with aortic [hazard ratio (HR) 2.87; 95% confidence interval (CI) 1.60-5.17; P < 0.001] or mitral (HR 3.50; 95% CI 1.47-8.07; P = 0.004) valve calcification, but this was not independent of coronary artery calcification or obstructive coronary artery disease.

CONCLUSION

Aortic and mitral valve calcification occurs in one in six patients with stable chest pain undergoing CCTA and is associated with concomitant coronary atherosclerosis. Whilst valvular calcification is associated with a higher risk of cardiovascular events, this was not independent of the burden of coronary artery disease.

Energy loss associated with in-vitro modeling of mitral annular calcification

Introduction

Study aims were to compare hemodynamics and viscous energy dissipation (VED) in 3D printed mitral valves–one replicating a normal valve and the other a valve with severe mitral annular calcification (MAC). Patients with severe MAC develop transmitral gradients, without the commissural fusion typifying rheumatic mitral stenosis (MS), and may have symptoms similar to classical MS. A proposed mechanism relates to VED due to disturbed blood flow through the diseased valve into the ventricle.

Methods

A silicone model of a normal mitral valve (MV) was created using a transesophageal echocardiography dataset. 3D printed calcium phantoms were incorporated into a second valve model to replicate severe MAC. The synthetic MVs were tested in a left heart duplicator under rest and exercise conditions. Fine particles were suspended in a water/glycerol blood analogue for particle image velocimetry calculation of VED.

Results

Catheter mean transmitral gradients were slightly higher in the MAC valve compared to the normal MV, both at rest (3.2 vs. 1.3 mm Hg) and with exercise (5.9 vs. 5.0 mm Hg); Doppler gradients were 2.7 vs. 2.1 mm Hg at rest and 9.9 vs 8.2 mm Hg with exercise. VED was similar between the two valves at rest. During exercise, VED increased to a greater extent for the MAC valve (240%) versus the normal valve (127%).

Conclusion

MAC MS is associated with slightly increased transmitral gradients but markedly increased VED during exercise. These energy losses may contribute to the exercise intolerance and exertional dyspnea present in MAC patients.

Cardiovascular Biomarkers and Imaging in Older Adults: JACC Council Perspectives

Whereas the burgeoning population of older adults is intrinsically vulnerable to cardiovascular disease, the utility of many management precepts that were validated in younger adults is often unclear. Whereas biomarker- and imaging-based tests are a major part of cardiovascular disease care, basic assumptions about their use and efficacy cannot be simply extrapolated to many older adults. Biology, physiology, and body composition change with aging, with important influences on cardiovascular disease testing procedures and their interpretation. Furthermore, clinical priorities of older adults are more heterogeneous, potentially undercutting the utility of testing data that are collected. The American College of Cardiology and the National Institutes on Aging, in collaboration with the American Geriatrics Society, convened, at the American College of Cardiology Heart House, a 2-day multidisciplinary workshop, "Diagnostic Testing in Older Adults with Cardiovascular Disease," to address these issues. This review summarizes key concepts, clinical limitations, and important opportunities for research.

Advances in Quantitative Analysis of 18F-Sodium Fluoride Coronary Imaging

¹⁸F-sodium fluoride (¹⁸F-NaF) positron emission tomography (PET) has emerged as a promising noninvasive imaging tool for the assessment of active calcification processes in coronary artery disease. ¹⁸F-NaF uptake colocalizes to high-risk and ruptured atherosclerotic plaques. Most recently, ¹⁸F-NaF coronary uptake was shown to be a robust and independent predictor of myocardial infarction in patients with advanced coronary artery disease. In this review, we provide an overview of the advances in coronary ¹⁸F-NaF imaging. In particular, we discuss the recently developed and validated motion correction techniques which address heart contractions, tidal breathing, and patient repositioning during the prolonged PET acquisitions. Additionally, we discuss a novel quantification approach—the coronary microcalcification activity (which has been inspired by the widely employed method in oncology total active tumor volume measurement). This new method provides a single number encompassing ¹⁸F-NaF activity within the entire coronary vasculature rather than just information regarding a single area of most intense tracer uptake.

Current Indications for Transcatheter Mitral Valve Replacement Using Transcatheter Aortic Valves

Use of transcatheter mitral valve replacement (TMVR) using transcatheter aortic valves in clinical practice is limited to patients with failing bioprostheses and rings or mitral valve disease associated with severe mitral annulus calcification. Whereas the use of valve-in-valve TMVR appears to be a reasonable alternative to surgery in patients at high surgical risk, much less evidence supports valve-in-ring and valve-in-mitral annulus calcification interventions. Data on the results of TMVR in these settings are derived from small case series or voluntary registries. This review summarizes the current evidence on TMVR using transcatheter aortic valves in clinical practice from the characteristics of the TMVR candidates, screening process, performance of the procedure, and description of current results and future perspectives. TMVR using dedicated devices in native noncalcified mitral valve diseases is beyond the scope of the article.

Coronary 18F-Fluoride Uptake and Progression of Coronary Artery Calcification

Supplemental Digital Content is available in the text.

Background

Positron emission tomography (PET) using ¹⁸F-sodium fluoride (¹⁸F-fluoride) to detect microcalcification may provide insight into disease activity in coronary atherosclerosis. This study aimed to investigate the relationship between ¹⁸F-fluoride uptake and progression of coronary calcification in patients with clinically stable coronary artery disease.

Methods

Patients with established multivessel coronary atherosclerosis underwent ¹⁸F-fluoride PET-computed tomography angiography and computed tomography calcium scoring, with repeat computed tomography angiography and calcium scoring at one year. Coronary PET uptake was analyzed qualitatively and semiquantitatively in diseased vessels by measuring maximum tissue-to-background ratio. Coronary calcification was quantified by measuring calcium score, mass, and volume.

Results

In a total of 183 participants (median age 66 years, 80% male), 116 (63%) patients had increased ¹⁸F-fluoride uptake in at least one vessel. Individuals with increased ¹⁸F-fluoride uptake demonstrated more rapid progression of calcification compared with those without uptake (change in calcium score, 97 [39–166] versus 35 [7–93] AU; P<0.0001). Indeed, the calcium score only increased in coronary segments with ¹⁸F-fluoride uptake (from 95 [30–209] to 148 [61–289] AU; P<0.001) and remained unchanged in segments without ¹⁸F-fluoride uptake (from 46 [16–113] to 49 [20–115] AU; P=0.329). Baseline coronary ¹⁸F-fluoride maximum tissue-to-background ratio correlated with 1-year change in calcium score, calcium volume, and calcium mass (Spearman ρ=0.37, 0.38, and 0.46, respectively; P<0.0001 for all). At the segmental level, baseline ¹⁸F-fluoride activity was an independent predictor of calcium score at 12 months (P<0.001). However, at the patient level, this was not independent of age, sex, and baseline calcium score (P=0.50).

Conclusions

Coronary ¹⁸F-fluoride uptake identifies both patients and individual coronary segments with more rapid progression of coronary calcification, providing important insights into disease activity within the coronary circulation. At the individual patient level, total calcium score remains an important marker of disease burden and progression.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02110303.

Case report: Metastatic cardiac calcifications in a patient with a history of rickets

Background

Metastatic cardiac calcifications are often seen in patients with renal failure and dialysis associated with vascular calcification and calcifications in other organs. There is little to no evidence of metastatic cardiac calcification in patients with a history of rickets.

Case summary

A 40-year-old patient with a history of rickets treated in infancy and no personal history of cardiovascular or renal disease came for a periodical examination. Transthoracic echocardiogram showed an important calcification in the mitral annulus and the mitro-aortic junction. Computed tomography (CT) showed marked calcification affecting the heart fibrous skeleton. Coronary arteries were not affected.

Discussion

Distribution of heart calcification seen both with echocardiography and CT is important to report so they can be identified as dystrophic or metastatic. These two have different aetiologies so the description may help identify the possible cause.

Implications of Renal Disease in Patients Undergoing Structural Interventions

Chronic kidney disease patients have a high prevalence of severe valvular heart disease, which reduces life expectancy. Transcatheter valve interventions has revamped the way we manage severe valvular heart disease and are an attractive alternative to invasive surgery in patients with chronic kidney disease and severe valvular heart disease. This review summarizes the impact of transcatheter valve interventions in patients with severe valvular heart disease and chronic kidney disease.

18F-Sodium Fluoride (18F-NaF) for Imaging Microcalcification Activity in the Cardiovascular System

Accumulating preclinical and clinical evidence suggests that calcification is one of the body's primary responses to injury and a key pathological feature of cardiovascular disease. Calcification activity can now be imaged using 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) in combination with either computed tomography or magnetic resonance. These techniques allow visualization of calcification activity and, therefore, provide different information to the established macroscopic calcium imaged with computed tomography. Indeed, 18F-NaF PET has been used to investigate a wide range of valvular conditions, including aortic stenosis, mitral annular calcification, and bioprosthetic valve disease, as well as vascular conditions, including abdominal aortic aneurysm disease, coronary, and carotid atherosclerosis, peripheral vascular disease, and erectile dysfunction. In this brief review, we will focus on how 18F-NaF PET has improved our pathophysiological understanding of cardiovascular calcification and how it can be used as a marker of vascular calcification, providing a useful tool that can be utilized in clinical trials investigating the prediction of both disease progression and clinical events. Finally, we will discuss how 18F-NaF might be employed clinically to improve patient assessment and to guide decision-making.