Adult Congenital Heart Disease Care in Canada: Has Quality of Care Improved in the Last Decade?

BACKGROUND

Patients with adult congenital heart disease (ACHD) are at increased risk of comorbidity and death compared with the age-matched population. Specialized care is shown to improve survival. The purpose of this study was to analyze current measures of quality of care in Canada compared with those published by our group in 2012.

METHODS

A survey focusing on structure and process measures of care quality in 2020 was sent to 15 ACHD centres registered with the Canadian Adult Congenital Heart Network. For each domain of quality, comparisons were made with those published in 2012.

RESULTS

In Canada, 36,708 patients with ACHD received specialized care between 2019 and 2020. Ninety-five cardiologists were affiliated with ACHD centres. The median number of patients per ACHD clinic was 2000 (interquartile range [IQR]: 1050, 2875). Compared with the 2012 results, this represents a 68% increase in patients with ACHD but only a 19% increase in ACHD cardiologists. Compared with 2012, all procedural volumes increased with cardiac surgeries, increasing by 12% and percutaneous intervention by 22%. Wait time for nonurgent consults and interventions all exceeded national recommendations by an average of 7 months and had increased compared with 2012 by an additional 2 months. Variability in resources were noted across provincial regions.

CONCLUSIONS

Over the past 10 years, ACHD care gaps have persisted, and personnel and infrastructure have not kept pace with estimates of ACHD population growth. Strategies are needed to improve and reduce disparity in ACHD care relative to training, staffing, and access to improved care for Canadians with ACHD.

The Impact of the COVID-19 Pandemic Restrictions on the Provision of Adult Congenital Heart Disease Care Across Canada: A National Survey

Background

The COVID-19 pandemic significantly impacted health care access across Canada with the reduction in in-person evaluations. The aim of the study was to examine the effects of the COVID-19 pandemic on access to health care services among the Canadian population with adult congenital heart disease (ACHD).

Methods

All Canadian adult congenital heart affiliated centres were contacted and asked to collect data on outpatient clinic and procedural volumes for the 2019 and 2020 calendar years. A survey was sent detailing questions on clinic and procedural volumes and wait times before and after pandemic restrictions. Descriptive statistics were used with the Student t-test to compare groups.

Results

In 2019, there were 19,326 ACHD clinic visits across Canada and only 296 (1.5%) virtual clinic visits. However, during the first year of the pandemic, there were 20,532 clinic visits and 11,412 (56%) virtual visits (P < 0.0001). There were no differences in procedural volumes (electrophysiology, cardiac surgery, and percutaneous intervention) between 2019 and 2020. The mean estimated wait times (months) before the pandemic vs the pandemic were as follows: nonurgent consult 5.4 ± 2.6 vs 6.6 ± 4.2 (P = 0.65), ACHD surgery 6.0 ± 3.5 vs 7.0 ± 4.6 (P = 0.47), electrophysiology procedures 6.3 ± 3.3 vs 5.7 ± 3.3 (P = 0.72), and percutaneous intervention 4.6 ± 3.9 vs 4.4 ± 2.3 (P = 0.74).

Conclusions

During the pandemic and restrictions of social distancing, the use of virtual clinic visits helped to maintain continuity in ACHD clinical care, with 56% of ACHD visits being virtual. The procedural volumes and wait times for consultation and percutaneous and surgical interventions were not delayed.

Arterial Age and Early Vascular Aging, But Not Chronological Age, Are Associated With Faster Thoracic Aortic Aneurysm Growth

Background Aneurysm size is an imperfect risk assessment tool for those with thoracic aortic aneurysm (TAA). Assessing arterial age may help TAA risk stratification, as it better reflects aortic health. We sought to evaluate arterial age as a predictor of faster TAA growth, independently of chronological age. Methods and Results We examined 137 patients with TAA. Arterial age was estimated according to validated equations, using patients' blood pressure and carotid-femoral pulse wave velocity. Aneurysm growth was determined prospectively from available imaging studies. Multivariable linear regression assessed the association of chronological age and arterial age with TAA growth, and multivariable logistic regression assessed associations of chronological and arterial age with the presence of accelerated aneurysm growth (defined as growth>median in the sample). Mean±SD chronological and arterial ages were 62.2±11.3 and 54.2±24.5 years, respectively. Mean baseline TAA size and follow-up time were 45.9±4.0 mm and 4.5±1.9 years, respectively. Median (interquartile range) TAA growth was 0.31 (0.14-0.52) mm/year. Older arterial age (ß±SE for 1 year: 0.004±0.001, P<0.0001) was independently associated with faster TAA growth, while chronological age was not (P=0.083). In logistic regression, each 5-year increase in arterial age was associated with a 23% increase in the odds of accelerated TAA growth (95% CI, 1.085-1.394; P=0.001). Conclusions Arterial age is independently associated with accelerated aneurysm expansion, while chronological age is not. Our results highlight that a noninvasive and inexpensive assessment of arterial age can potentially be useful for TAA risk stratification and disease monitoring as compared with the current clinical standard (chronological age).

Aortic Stenosis Progression: A Systematic Review and Meta-Analysis

BACKGROUND

Aortic valve stenosis is a progressive disorder with variable progression rates. The factors affecting aortic stenosis (AS) progression remain largely unknown.

OBJECTIVES

This systematic review and meta-analysis sought to determine AS progression rates and to assess the impact of baseline AS severity and sex on disease progression.

METHODS

The authors searched Medline, Embase, and the Cochrane Central Register of Controlled Trials from inception to July 1, 2020, for prospective studies evaluating the progression of AS with the use of echocardiography (mean gradient [MG], peak velocity [PV], peak gradient [PG], or aortic valve area [AVA]) or computed tomography (calcium score [AVC]). Random-effects meta-analysis was performed to evaluate the rate of AS progression for each parameter stratified by baseline severity, and meta-regression was performed to determine the impact of baseline severity and of sex on AS progression rate.

RESULTS

A total of 24 studies including 5,450 patients (40% female) met inclusion criteria. The pooled annualized progression of MG was +4.10 mm Hg (95% CI: 2.80-5.41 mm Hg), AVA -0.08 cm² (95% CI: 0.06-0.10 cm²), PV +0.19 m/s (95% CI: 0.13-0.24 m/s), PG +7.86 mm Hg (95% CI: 4.98-10.75 mm Hg), and AVC +158.5 AU (95% CI: 55.0-261.9 AU). Increasing baseline severity of AS was predictive of higher rates of progression for MG (P < 0.001), PV (P = 0.001), and AVC (P < 0.001), but not AVA (P = 0.34) or PG (P = 0.21). Only 4 studies reported AS progression stratified by sex, with only PV and AVC having 3 studies to perform a meta-analysis. No difference between sex was observed for PV (P = 0.397) or AVC (P = 0.572), but the level of confidence was low.

CONCLUSIONS

This study provides progression rates for both hemodynamic and anatomic parameters of AS and shows that increasing hemodynamic and anatomic baseline severity is associated with faster AS progression. More studies are needed to determine if sex differences affect AS progression. (Aortic Valve Stenosis Progression Rate: A Systematic Review and Meta-Analysis; CRD42021207726).

Combining Aortic Size With Arterial Hemodynamics Enhances Assessment of Future Thoracic Aortic Aneurysm Expansion

BACKGROUND

Thoracic aortic aneurysm (TAA) is a deadly disease whose current method for risk stratification (aneurysm size) is imperfect. We sought to evaluate whether combining aortic size with hemodynamic measures that reflect the aorta's function was superior to aortic size alone in the assessment of TAA expansion.

METHODS

One hundred thirty-seven nonoperated participants with TAA were followed prospectively. Aortic stiffness and pulsatile hemodynamics were noninvasively assessed at baseline with a combination of arterial tonometry with echocardiography using validated methodology. Aneurysm growth was calculated from standard imaging modalities. Multivariable linear regression models adjusted for potential confounders evaluated the association of aneurysm size and arterial hemodynamics, alone and in combination, with TAA growth.

RESULTS

Sixty-nine percent of participants were male. Mean ± SD age, baseline aneurysm size, follow-up, and aneurysm expansion were, respectively, 62.2 ± 11.4 years, 45.9 ± 4.0 mm, 4.5 ± 1.9 years, and 0.41 ± 0.46 mm/year. In the linear regression models, the standardised β (β∗) for the association of aneurysm size with aneurysm expansion was 0.178 (P = 0.044). This was improved by combining aortic size with most measures of aortic function, with β∗ ranging from 0.192 (for aneurysm size combined with central diastolic blood pressure) to 0.484 (for aneurysm size combined with carotid-femoral pulse-wave velocity) (P ≤ 0.05 for each).

CONCLUSIONS

Combining aneurysm size with measures of arterial function improves assessment of aneurysm growth over TAA size alone, which is the standard for clinical decisions in TAA. Thus, combining aneurysm size with measures of aortic function provides a clinical advantage in the assessment of TAA disease activity.

Estimated Aortic Pulse Wave Velocity Is Associated With Faster Thoracic Aortic Aneurysm Growth: A Prospective Cohort Study With Sex-Specific Analyses

BACKGROUND

Thoracic aortic aneurysm (TAA) is associated with high morbidity and mortality, and there is a critical need for improved tools for risk assessment and prognostication. We have previously shown that aortic stiffness, measured from arterial tonometry (carotid-femoral pulse wave velocity [cfPWV]), is independently associated with TAA expansion. To increase clinical applicability, we sought to determine the association of mathematically estimated aortic pulse wave velocity (e-PWV) with TAA expansion.

METHODS

One-hundred and five consecutive unoperated subjects with TAA were recruited. We used arterial tonometry to measure cfPWV and used mean arterial pressure and age to calculate e-PWV according to validated equations. Multivariable linear regression assessed associations of baseline e-PWV with future aneurysm growth. Given sex differences in TAA outcomes, sex-stratified analyses were performed.

RESULTS

Seventy-eight percent of subjects were men. Mean ± standard deviation (SD) age, baseline aneurysm size, and follow-up time were 62.6 ± 11.4 years, 46.2 ± 3.8 mm, and 2.9 ± 1.0 years, respectively. Aneurysm growth was 0.43 ± 0.37 mm per year; e-PWV was independently associated with future aneurysm expansion (β ± SE: 0.240 ± 0.085, P = 0.006). In sex-specific analyses, e-PWV was associated with aneurysm growth in both men (β ± standard error (SE) : 0.076 ± 0.022, P = 0.001) and women (β ± SE : 0.145 ± 0.050, P = 0.012), but the strength of association nearly twice as strong in women as in men.

CONCLUSIONS

Greater aortic stiffness reflects worse aortic health and provides novel insights into disease activity; e-PWV is independently associated with TAA growth. This finding increases clinical applicability, as e-PWV can be estimated simply, quickly, and free of cost without the need for specialized equipment.

Canadian Cardiovascular Society 2022 Guidelines for Cardiovascular Interventions in Adults With Congenital Heart Disease

Interventions in adults with congenital heart disease (ACHD) focus on surgical and percutaneous interventions in light of rapidly evolving ACHD clinical practice. To bring rigour to our process and amplify the cumulative nature of evidence ACHD care we used the ADAPTE process; we systematically adjudicated, updated, and adapted existing guidelines by Canadian, American, and European cardiac societies from 2010 to 2020. We applied this to interventions related to right and left ventricular outflow obstruction, tetralogy of Fallot, coarctation, aortopathy associated with bicuspid aortic valve, atrioventricular canal defects, Ebstein anomaly, complete and congenitally corrected transposition, and patients with the Fontan operation. In addition to tables indexed to evidence, clinical flow diagrams are included for each lesion to facilitate a practical approach to clinical decision-making. Excluded are recommendations for pacemakers, defibrillators, and arrhythmia-directed interventions covered in separate designated documents. Similarly, where overlap occurs with other guidelines for valvular interventions, reference is made to parallel publications. There is a paucity of high-level quality of evidence in the form of randomized clinical trials to support guidelines in ACHD. We accounted for this in the wording of the strength of recommendations put forth by our national and international experts. As data grow on long-term follow-up, we expect that the evidence driving clinical practice will become increasingly granular. These recommendations are meant to be used to guide dialogue between clinicians, interventional cardiologists, surgeons, and patients making complex decisions relative to ACHD interventions.

Natural History of Mitral Annulus Calcification and Calcific Mitral Valve Disease

BACKGROUND

The natural history of mitral annular calcification (MAC) and risk for developing calcific mitral valve disease (CMVD) has been poorly defined. We sought to evaluate the progression rate of MAC and of the development of CMVD.

METHODS

Patients with MAC and paired echocardiograms at least one year apart between 2005 and 2019 were included. Progression rates from mild/moderate to severe MAC and to CMVD (defined as severe MAC and significant mitral stenosis and/or regurgitation) were assessed, along with potential association with sex.

RESULTS

A total of 11,605 patients (73±10years, 51%male) with MAC (78% mild, 17% moderate, 5% severe) were included and had a follow up echocardiogram at 4.2±2.7years. In patients with mild/moderate MAC, 33% presented with severe MAC at 10 years. The rate of severe MAC was higher in females than in males (41% vs. 24%, P<0.001, HR=1.3, P<0.001) and in patients with moderate vs. mild MAC (71% vs. 22%, P<0.001, HR=6.1, P<0.001). At 10 years 10% presented with CMVD (4%, 23% and 60% in patients with mild, moderate, and severe MAC respectively) and was predicted by female sex (15% vs. 5%, P<0.0001), even after adjustment for MAC severity (HR=1.9, P<0.001).

CONCLUSION

In this large cohort of patients with MAC, progression to severe MAC was common and frequently results in CMVD. Female sex was associated with higher progression rates. MAC and CMVD are expected to dramatically increase as the population ages highlighting the importance of a better understanding of the pathophysiology of MAC in order to develop effective preventive medical therapies.

Central Hypertension in Patients With Thoracic Aortic Aneurysms: Prevalence and Association With Aneurysm Size and Growth

BACKGROUND

Hypertension (HTN) has the greatest population-attributable risk for aortic dissection and is highly prevalent among patients with thoracic aortic aneurysms (TAAs). Although HTN is diagnosed based on brachial blood pressure (bBP), central HTN (central systolic blood pressure [cSBP] ≥130 mm Hg) is of interest as it better reflects blood pressure (BP) in the aorta. We aimed to (i) evaluate the prevalence of central HTN among TAA patients without a diagnosis of HTN, and (ii) assess associations of bBP vs. central blood pressure (cBP) with aneurysm size and growth.

METHODS

One hundred and five unoperated subjects with TAAs were recruited. With validated methodology, cBP was assessed with applanation tonometry. Aneurysm size was assessed at baseline and follow-up using imaging modalities. Aneurysm growth rate was calculated in mm/year. Multivariable linear regression adjusted for potential confounders assessed associations of bBP and cBP with aneurysm size and growth.

RESULTS

Seventy-seven percent of participants were men and 49% carried a diagnosis of HTN. Among participants without diagnosis of HTN, 15% had central HTN despite normal bBP ("occult central HTN"). In these patients, higher central systolic BP (cSBP) and central pulse pressure (cPP) were independently associated with larger aneurysm size (β ± SE = 0.28 ± 0.11, P = 0.014 and cPP = 0.30 ± 0.11, P = 0.010, respectively) and future aneurysm growth (β ± SE = 0.022 ± 0.008, P = 0.013 and 0.024 ± 0.009, P = 0.008, respectively) while bBP was not (P > 0.05).

CONCLUSIONS

In patients with TAAs without a diagnosis of HTN, central HTN is prevalent, and higher cBP is associated with larger aneurysms and faster aneurysm growth.

Size-adjusted aortic valve area: refining the definition of severe aortic stenosis

AIMS

Severe aortic valve stenosis (AS) is defined by an aortic valve area (AVA) <1 cm2 or an AVA indexed to body surface area (BSA) <0.6 cm/m2, despite little evidence supporting the latter approach and important intrinsic limitations of BSA indexation. We hypothesized that AVA indexed to height (H) might be more applicable to a wide range of populations and body morphologies and might provide a better predictive accuracy.

METHODS AND RESULTS

In 1298 patients with degenerative AS and preserved ejection fraction from three different countries and continents (derivation cohort), we aimed to establish an AVA/H threshold that would be equivalent to 1.0 cm2 for defining severe AS. In a distinct prospective validation cohort of 395 patients, we compared the predictive accuracy of AVA/BSA and AVA/H. Correlations between AVA and AVA/BSA or AVA/H were excellent (all R2 > 0.79) but greater with AVA/H. Regressions lines were markedly different in obese and non-obese patients with AVA/BSA (P < 0.0001) but almost identical with AVA/H (P = 0.16). AVA/BSA values that corresponded to an AVA of 1.0 cm2 were markedly different in obese and non-obese patients (0.48 and 0.59 cm2/m2) but not with AVA/H (0.61 cm2/m for both). Agreement for the diagnosis of severe AS (AVA < 1 cm2) was significantly higher with AVA/H than with AVA/BSA (P < 0.05). Similar results were observed across the three countries. An AVA/H cut-off value of 0.6 cm2/m [HR = 8.2(5.6-12.1)] provided the best predictive value for the occurrence of AS-related events [absolute AVA of 1 cm2: HR = 7.3(5.0-10.7); AVA/BSA of 0.6 cm2/m2 HR = 6.7(4.4-10.0)].

CONCLUSION

In a large multinational/multiracial cohort, AVA/H was better correlated with AVA than AVA/BSA and a cut-off value of 0.6 cm2/m provided a better diagnostic and prognostic value than 0.6 cm2/m2. Our results suggest that severe AS should be defined as an AVA < 1 cm2 or an AVA/H < 0.6 cm2/m rather than a BSA-indexed value of 0.6 cm2/m2.

Single vs. Serial Assessments of Arterial Hemodynamics to Predict Thoracic Aortic Aneurysm (TAA) Expansion

BACKGROUND

Thoracic aortic aneurysm (TAA) is a highly morbid disease. We have previously shown that baseline hemodynamic measures reflecting aortic function (AoFx) are associated with future TAA expansion. However, whether serial arterial hemodynamic assessment further improves TAA growth assessment remains unknown. Thus, we aimed to compare single vs. serial arterial hemodynamic assessments in the evaluation of future TAA growth.

METHODS

Eighty-six unoperated participants with TAA underwent non-invasive arterial hemodynamic assessment using arterial tonometry and echocardiography at baseline and after 1-year. Aortic diameter was measured serially with standard imaging modalities. Stepwise multivariable linear regression was used to assess associations of baseline and 1-year change (Δ) in arterial hemodynamic measures with TAA growth.

RESULTS

Mean age was 62.7±11.0 years; 79% were male. Mean±SD aneurysm growth was 0.48±0.54 mm/year after a follow-up of 2.96±1.03 years. Yearly changes in arterial hemodynamic measures ranged from -3.2% to +4.2%. Linear regression results showed that while baseline arterial hemodynamic measures were independently associated with aneurysm growth (carotid-femoral pulse wave velocity: ß±SE = 0.038±0.013; aortic characteristic impedance: ß±SE=0.002±0.00; proximal aortic compliance: ß±SE= -0.011±0.006; forward pressure wave amplitude: ß±SE 0.009±0.002; reflected pressure wave amplitude: ß±SE= 0.017±0.006. p<0.05 for each), the 1-year Δ in these measures did not incrementally add to aneurysm growth assessment (p>0.05 for each Δ).

CONCLUSION

While baseline measures of AoFx independently predict TAA expansion, 1-year changes in these measures do not improve this prediction. Thus, for TAA risk assessment purposes, a baseline assessment of AoFx may suffice, which simplifies its use for potential predictive algorithms.

Clinical implications of left atrial size adjustment: Impact of obesity

BACKGROUND

American and European societies recommend using left atrial (LA) volume adjusted to body surface area (BSA) as the means of indexing LA volume to the patient's body size irrespective of morphometric characteristics.

AIM

To evaluate the impact of obesity on LA volume indexation to BSA on the presence and degree of LA enlargement.

METHODS

From our echocardiography database, we extracted all consecutive adults referred for a transthoracic echocardiography in 2019 (n=28,725; 64±17 years; 55% male; 31% obese [body mass index≥30kg/m²]). LA volume indexed to BSA was calculated using measured weight (LA_Meas) and ideal weight (LA_Ideal) calculated using the Devine Formula.

RESULTS

LA_Meas and LA_Ideal were 35±17mL/m² and 40±19mL/m², respectively (P<0.0001); 13% were classified as having a normal LA_Meas but LA_Ideal enlargement overall, 25% in obese patients and 7% in non-obese patients (P<0.0001). The percentages of patients with no, mild, moderate and severe LA dilatation were 57%, 19%, 9% and 16%, respectively, using LA_Meas, and 45%, 20%, 11% and 24%, respectively, using LA_Ideal (kappa=0.57). Degree of LA enlargement differed in 8194 patients (29%); 96% of the disagreement was related to underestimation of the degree of LA enlargement using LA_Meas. Agreement for the degree of LA enlargement was poor in obese and good in non-obese patients (kappa=0.28 and 0.71, respectively). As illustrative clinical implications, diastolic function grade was modified in 8.3% of patients with preserved ejection fraction and 10.8% of patients with reduced left ventricular ejection fraction/myocardial disease, and timing for intervention was potentially different in 12.9% of patients with primary mitral regurgitation.

CONCLUSIONS

Indexing LA volume to measured BSA versus ideal BSA markedly underestimates the presence and severity of LA enlargement, especially in obese patients, with potential important clinical implications.

Aortic Stiffness, Central Blood Pressure, and Pulsatile Arterial Load Predict Future Thoracic Aortic Aneurysm Expansion

Thoracic aortic aneurysm is a disease associated with high morbidity and mortality. Clinically useful strategies for medical management of thoracic aortic aneurysm are critically needed. To address this need, we sought to determine the role of aortic stiffness and pulsatile arterial load on future aneurysm expansion. One hundred five consecutive, unoperated subjects with thoracic aortic aneurysm were recruited and prospectively followed. By combining arterial tonometry with echocardiography, we estimated measures of aortic stiffness, central blood pressure, steady, and pulsatile arterial load at baseline. Aneurysm size was measured at baseline and follow-up with imaging; growth was calculated in mm/y. Stepwise multivariable linear regression assessed associations of arterial stiffness and load measures with aneurysm growth after adjusting for potential confounders. Mean±SD age, baseline aneurysm size, and follow-up time were 62.6±11.4 years, 46.24±3.84 mm, and 2.92±1.01 years, respectively. Aneurysm growth rate was 0.43±0.37 mm/y. After correcting for multiple comparisons, higher central systolic (β±SE: 0.026±0.009, P=0.007), and pulse pressures (β±SE: 0.032±0.009, P=0.0002), carotid-femoral pulse wave velocity (β±SE: 0.032±0.011, P=0.005), amplitudes of the forward (β±SE: 0.044±0.012, P=0.0003) and reflected (β±SE: 0.060±0.020, P=0.003) pressure waves, and lower total arterial compliance (β±SE: -0.086±0.032, P=0.009) were independently associated with future aneurysm growth. Measures of aortic stiffness and pulsatile hemodynamics are independently associated with future thoracic aortic aneurysm growth and provide novel insights into disease activity. Our findings highlight the role of central hemodynamic assessment to tailor novel risk assessment and therapeutic strategies to patients with thoracic aortic aneurysm.

Role of estimated aortic pulse wave velocity in the prediction of future thoracic aortic aneurysm expansion

Background

Thoracic aortic aneurysm (TAA) is a deadly disease in critical need of novel strategies for risk assessment and medical management. To address this need, we have previously shown that directly measured carotid-femoral pulse wave velocity (cfPWV), a marker of aortic stiffness and health, independently predicts future TAA expansion. Since aortic pulse wave velocity can be estimated from age and mean arterial pressure (MAP), in the present study we sought to determine whether estimated aortic pulse wave velocity (e-aPWV) also predicts TAA expansion.

Methods

One hundred and five consecutive, unoperated subjects with TAA were recruited. e-aPWV was estimated from validated equations based on age and MAP. cfPWV was measured with arterial tonometry according to guidelines. TAA size was measured at baseline and at the latest follow-up using available imaging modalities according to guidelines. Stepwise multivariable linear regression (P≤0.25 to enter, P≤0.10 to stay in the model) assessed independent associations of e-aPWV and cfPWV with future TAA growth. Variables considered in the models were: age, sex, BSA, MAP, TAA etiology and location, baseline TAA size, follow-up time, imaging modality, history of hypertension, diabetes and smoking.

Results

Seventy eight percent of subjects were men. Mean±SD age, baseline aneurysm size and follow-up time were 62.6±11.4 years, 46.2±3.8 mm and 3.0±1.0 years, respectively. e-aPWV and cfPWV were moderately correlated (Pearson's correlation coefficient = 0.61). Results of the linear regression analyses showed that both measured (cfPWV) and estimated (e-aPWV) independently predicted future TAA expansion (β±SE: 0.032±0.011, P=0.048 and 0.240±0.085, P=0.006, respectively). The base model's R-squared value of 0.39 was increased to 0.44 with addition of either cfPWV or e-aPWV to the model, confirming that each parameter of aortic stiffness enhances prediction of TAA growth.

Conclusion

Aortic stiffness is relevant for assessment of TAA disease activity. Similar to cfPWV, e-aPWV is also independently associated with future TAA expansion. Thus, e-aPWV represents a tool to improve TAA risk stratification that is simple, free of cost, and obviates the need for specialized equipment or dedicating training, which leads to excellent potential for widespread incorporation into clinical practice.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Canadian Institutes of Health Research

Thoracic Aortic Aneurysm Growth in Bicuspid Aortic Valve Patients: Role of Aortic Stiffness and Pulsatile Hemodynamics

Background

Bicuspid aortic valve (BAV) is the most common congenital cardiac abnormality. A thoracic aortic aneurysm (TAA) is present in ≈50% of BAV patients, who also have an 8‐fold higher risk of aortic dissection than the general population. Because the health of the aorta is directly reflected in its stiffness and pulsatile hemodynamics, we hypothesized that measures of aortic stiffness and arterial load would be associated with TAA growth in BAV.

Methods and Results

Twenty‐nine unoperated participants with TAA due to BAV who had serial imaging were recruited. Aortic stiffness and steady and pulsatile arterial load were evaluated with validated methods that integrate arterial tonometry with echocardiography. TAA growth was assessed retrospectively based on available imaging, blinded to hemodynamic status. Multivariable linear regression assessed associations of aortic stiffness and hemodynamic variables with TAA growth, adjusting for potential confounders. Overall, 66% of participants were men. Mean±SD for age, baseline aneurysm size, growth rate, and follow‐up time were 57.2±8.3 years, 46.9±3.6 mm, 0.75±0.81 mm/y, and 2.9±3.3 years, respectively. We found that greater aortic stiffness (β±SE for carotid‐femoral pulse wave velocity: 0.30±0.13. P=0.03) and aortic characteristic impedance (β±SE: 0.46±0.18, P=0.02), as well as lower total arterial and proximal aortic compliance (β±SE: −0.44±0.21, P=0.05, and −0.63±0.16, P=0.001, respectively) were independently associated with faster aneurysm growth.

Conclusions

In patients with TAA due to BAV, measures of greater aortic stiffness and pulsatile arterial load indicate an association with accelerated aneurysm expansion. Assessing arterial hemodynamics may be useful for risk stratification and disease monitoring in TAA patients with BAV.

Presentation and management of calcific mitral valve disease

Little is known about the prevalence, presentation and management of calcific mitral valve disease (CMVD). We identified 167 patients (80 ± 10 years; 79% women) with significant CMVD undergoing transthoracic echocardiography at our institution in 2016. Patients presented with significant co-morbidities, 47% had moderate/severe mitral stenosis, 38% had 3+/4+ mitral regurgitation and 15% had a combination of both. Fifty-eight percent were symptomatic. Most symptomatic patients were managed conservatively and incurred higher mortality and mortality/heart failure admission rates than those managed surgically. These data highlight the importance of gaining mechanistic insights into CMVD to prevent its occurrence and avoid the need for high-risk surgery, which is seldom performed in contemporary practice.

Tricuspid Intervention Following Pulmonary Valve Replacement in Adults With Congenital Heart Disease

BACKGROUND

Tricuspid regurgitation (TR) is common among adults with corrected tetralogy of Fallot (TOF) or pulmonary stenosis (PS) referred for pulmonary valve replacement (PVR). Yet, combined valve surgery remains controversial.

OBJECTIVES

This study sought to evaluate the impact of concomitant tricuspid valve intervention (TVI) on post-operative TR, length of hospital stay, and on a composite endpoint consisting of 7 early adverse events (death, reintervention, cardiac electronic device implantation, infection, thromboembolic event, hemodialysis, and readmission).

METHODS

The national Canadian cohort enrolled 542 patients with TOF or PS and mild to severe TR who underwent isolated PVR (66.8%) or PVR+TVI (33.2%). Outcomes were abstracted from charts and compared between groups using multivariable logistic and negative binomial regression.

RESULTS

Median age at reintervention was 35.3 years. Regardless of surgery type, TR decreased by at least 1 echocardiographic grade in 35.4%, 66.9%, and 92.8% of patients with pre-operative mild, moderate, and severe insufficiency. In multivariable analyses, PVR+TVI was associated with an additional 2.3-fold reduction in TR grade (odds ratio [OR]: 0.44; 95% confidence interval [CI]: 0.25 to 0.77) without an increase in early adverse events (OR: 0.85; 95% CI: 0.46 to 1.57) or hospitalization time (incidence rate ratio: 1.17; 95% CI: 0.93 to 1.46). Pre-operative TR severity and presence of transvalvular leads independently predicted post-operative TR. In contrast, early adverse events were strongly associated with atrial tachyarrhythmia, extracardiac arteriopathy, and a high body mass index.

CONCLUSIONS

In patients with TOF or PS and significant TR, concomitant TVI is safe and results in better early tricuspid valve competence than isolated PVR.

P5604Combining aortic size with measures of aortic stiffness and pulsatile hemodynamics enhances prediction of future thoracic aortic aneurysm expansion

Introduction

Thoracic aortic aneurysm (TAA) is a clinically silent disease which can lead to significant morbidity when complicated by an acute aortic syndrome. Although TAA size is the only variable used in decision-making, it is an imperfect predictor of risk. Conversely, hemodynamic measures that reflect the aorta's function, such as aortic stiffness and pulsatile hemodynamics, may provide additional insights into risk of TAA expansion.

Purpose

We hypothesized that combining aortic size with measures of arterial function (stiffness and pulsatile hemodynamics) would improve prediction of TAA expansion, as compared to aortic size alone.

Methods

105 unoperated participants with TAA were recruited between 2014 and 2017 and followed prospectively for ≥1 yr. TAA size was measured at enrolment and at the latest imaging study according to published consensus; TAA expansion was calculated as mm/year. Arterial function was non-invasively assessed at baseline with validated methods that integrate arterial tonometry with echocardiography. Multivariable linear regression assessed independent associations of baseline TAA size and each arterial function measure, initially separately and then in combination (by multiplying them when direction of association was the same, and dividing them when direction of association was opposite), with future TAA expansion. Standardized beta coefficients were calculated to allow direct comparisons. Models were adjusted for age, sex, body size, aneurysm location and etiology, type of imaging modality, follow-up time, mean arterial pressure, and history of hypertension, diabetes and smoking.

Results

Seventy-seven percent of participants were men, and the ratio of degenerative to heritable TAAs was 62/43. Mean ± SD age, baseline TAA size, and follow-up time were 62.8±11.3yrs, 46.3±3.9cm, and 2.2±0.7 years, respectively. Results of the multivariable linear regression models are summarized in the Table. While baseline TAA size and each arterial function measure were independently associated with TAA expansion, some of the arterial function measures were superior in predicting TAA growth (Table, left). In addition, combining aortic size and function further improved the prediction of TAA growth beyond each variable alone (Table, right).

Conclusion(s)

Combining aortic size with arterial function improved prediction of TAA expansion over any individual variable alone, independently of confounders. Assessing arterial function may confer a clinical advantage, when compared to current practice, in determining TAA disease activity and estimating one's TAA-related risk.

Acknowledgement/Funding

Canadian Institute of Health Research, Canadian Vascular Network, and Heart and Stroke Foundation of Canada

Novel pathogenic SMAD2 variants in five families with arterial aneurysm and dissection: further delineation of the phenotype

BACKGROUND

Missense variants in SMAD2, encoding a key transcriptional regulator of transforming growth factor beta signalling, were recently reported to cause arterial aneurysmal disease.

OBJECTIVES

The aims of the study were to identify the genetic disease cause in families with aortic/arterial aneurysmal disease and to further define SMAD2 genotype-phenotype correlations.

METHODS AND RESULTS

Using gene panel sequencing, we identified a SMAD2 nonsense variant and four SMAD2 missense variants, all affecting highly conserved amino acids in the MH2 domain. The premature stop codon (c.612dup; p.(Asn205*)) was identified in a marfanoid patient with aortic root dilatation and in his affected father. A p.(Asn318Lys) missense variant was found in a Marfan syndrome (MFS)-like case who presented with aortic root aneurysm and in her affected daughter with marfanoid features and mild aortic dilatation. In a man clinically diagnosed with Loeys-Dietz syndrome (LDS) that presents with aortic root dilatation and marked tortuosity of the neck vessels, another missense variant, p.(Ser397Tyr), was identified. This variant was also found in his affected daughter with hypertelorism and arterial tortuosity, as well as his affected mother. The third missense variant, p.(Asn361Thr), was discovered in a man presenting with coronary artery dissection. Variant genotyping in three unaffected family members confirmed its absence. The last missense variant, p.(Ser467Leu), was identified in a man with significant cardiovascular and connective tissue involvement.

CONCLUSION

Taken together, our data suggest that heterozygous loss-of-function SMAD2 variants can cause a wide spectrum of autosomal dominant aortic and arterial aneurysmal disease, combined with connective tissue findings reminiscent of MFS and LDS.

Thoracic Aortic Aneurysm Growth: Role of Sex and Aneurysm Etiology

BACKGROUND

Thoracic aortic aneurysm (TAA) outcomes are worse in women than men, although reasons for sex differences are unknown. Because faster TAA growth is a risk factor for acute aortic syndromes, we sought to determine the role of sex and aneurysm etiology on TAA growth.

METHODS AND RESULTS

Eighty-two consecutive unoperated subjects with TAA who had serial aneurysm measurements were recruited. In multivariable linear regression the association of female sex with aneurysm growth rate was assessed after adjustment for potential confounders. We also tested the interaction term sex×aneurysm etiology in the prediction of TAA growth. Seventy-four percent of subjects were men; mean±SD age was 62.4±11.9 years in men and 67.7±10.7 years in women (P=0.06). Forty-seven (57%) subjects had degenerative TAAs, and the remainder had heritable TAAs. Absolute baseline aneurysm size and follow-up time were not different between men and women. Aneurysm growth rate was 1.19±1.15 mm/y in women and 0.59±0.66 mm/y in men (P=0.02). Female sex remained significantly associated with greater aneurysm growth in multivariable analyses (β±SE: 0.35±0.12, P=0.005). In addition, female sex was associated with faster TAA growth only among those with degenerative TAA (β±SE: 0.33±0.08, P=0.0002) and not among those with heritable TAA (P=0.79), with a significant sex×etiology interaction (P=0.001).

CONCLUSIONS

TAA growth rates are greater in women than men, and this difference is specific to women with degenerative TAAs. Our findings may explain sex differences in TAA outcomes and provide a foundation for future investigations of this topic.

Posterior mitral abscess with bypass grafting before annulus reconstruction: a case report

A posterior mitral annular abscess is a rare but severe complication of endocarditis which requires careful surgical intervention. The debridement and reconstruction can cause fatal complications such as left atrioventricular groove rupture, coronary artery entrapment, and acute myocardial infarction. We report on a 60-year-old woman who developed acute infective endocarditis of her native mitral valve complicated by a posterior annular abscess, and who underwent precautionary bypass grafting to a dominant circumflex coronary artery before extensive atrioventricular groove debridement and reconstruction.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: executive summary

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. They have distinctive forms of heart failure, and their cardiac disease can be associated with pulmonary hypertension, thromboemboli, complex arrhythmias and sudden death.Medical aspects that need to be considered relate to the long-term and multisystemic effects of single-ventricle physiology, cyanosis, systemic right ventricles, complex intracardiac baffles and failing subpulmonary right ventricles. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with CHD, there have been significant advances in the understanding of the late outcomes, genetics, medical therapy and interventional approaches in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. The present executive summary is a brief overview of the new guidelines and includes the recommendations for interventions. The complete document consists of four manuscripts that are published online in the present issue of The Canadian Journal of Cardiology, including sections on genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy and contraception risks, and follow-up requirements. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: outflow tract obstruction, coarctation of the aorta, tetralogy of Fallot, Ebstein anomaly and Marfan's syndrome

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with CHD, there have been significant advances in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. Part II of the guidelines includes recommendations for the care of patients with left ventricular outflow tract obstruction and bicuspid aortic valve disease, coarctation of the aorta, right ventricular outflow tract obstruction, tetralogy of Fallot, Ebstein anomaly and Marfan's syndrome. Topics addressed include genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy risk and follow-up requirements. The complete document consists of four manuscripts that are published online in the present issue of The Canadian Journal of Cardiology. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: introduction

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. Since the 2001 Canadian Cardiovascular Society consensus conference report on the management of adults with CHD, there have been significant advances in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. The present introductory section is a summary of the epidemiology and scope of adult CHD in Canada, the structure of the Canadian health care system and adult congenital cardiac health services in Canada. The recommendations for antibiotic prophylaxis and genetic evaluation in this population are included. The complete document consists of four manuscripts, which are published online in the present issue of The Canadian Journal of Cardiology, including sections on genetics, outcomes, diagnostic workups, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy and contraception risks, and follow-up recommendations. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

Whipple's disease with constrictive pericarditis: a rare disease with a rare presentation

Whipple's disease is a multisystem disease that can affect the heart with predominantly endocardial and pericardial involvement and, less often, myocardial inflammation. Previously diagnosed at autopsy, cardiac involvement in Whipple's disease is being recognized clinically more often. A 58-year-old man with Whipple's-related constrictive pericarditis, arthralgias and lymphadenopathy is described. He underwent antibiotic treatment and pericardiectomy with improvement in his clinical state.

Implantable cardioverter-defibrillators in tetralogy of Fallot

BACKGROUND

Tetralogy of Fallot is the most common form of congenital heart disease in implantable cardioverter-defibrillator (ICD) recipients, yet little is known about the value of ICDs in this patient population.

METHODS AND RESULTS

We conducted a multicenter cohort study in high-risk patients with Tetralogy of Fallot to determine actuarial rates of ICD discharges, identify risk factors, and characterize ICD-related complications. A total of 121 patients (median age 33.3 years; 59.5% male) were enrolled from 11 sites and followed up for a median of 3.7 years. ICDs were implanted for primary prevention in 68 patients (56.2%) and for secondary prevention in 53 (43.8%), defined by clinical sustained ventricular tachyarrhythmia or resuscitated sudden death. Overall, 37 patients (30.6%) received at least 1 appropriate and effective ICD discharge, with a median ventricular tachyarrhythmia rate of 213 bpm. Annual actuarial rates of appropriate ICD shocks were 7.7% and 9.8% in primary and secondary prevention, respectively (P=0.11). A higher left ventricular end-diastolic pressure (hazard ratio 1.3 per mm Hg, P=0.004) and nonsustained ventricular tachycardia (hazard ratio 3.7, P=0.023) independently predicted appropriate ICD shocks in primary prevention. Inappropriate shocks occurred in 5.8% of patients yearly. Additionally, 36 patients (29.8%) experienced complications, of which 6 (5.0%) were acute, 25 (20.7%) were late lead-related, and 7 (5.8%) were late generator-related complications. Nine patients died during follow-up, which corresponds to an actuarial annual mortality rate of 2.2%, which did not differ between the primary and secondary prevention groups.

CONCLUSIONS

Patients with tetralogy of Fallot and ICDs for primary and secondary prevention experience high rates of appropriate and effective shocks; however, inappropriate shocks and late lead-related complications are common.

Potential utility of rubidium 82 PET quantification in patients with 3-vessel coronary artery disease

BACKGROUND

Standard perfusion imaging may underestimate the extent of disease in 3-vessel coronary atherosclerosis. This study determined whether positron emission tomography quantification of perfusion reserve by use of rubidium 82 net retention defined a greater extent of disease than the standard approach in patients with 3-vessel disease.

METHODS AND RESULTS

Rb-82 net retention was quantified as an estimation of absolute perfusion at rest and with dipyridamole stress by use of dynamic positron emission tomography imaging. The percent of abnormal myocardial sectors, as compared with a normal database, for a standard and quantification approach was determined. Twenty-three patients were evaluated. Defect sizes were larger in patients with 3-vessel disease (n = 13) by use of quantification methods: 44% +/- 18% of the myocardial sectors were abnormal by use of the standard approach versus 69% +/- 24% of sectors when measured by quantification of the stress-rest perfusion difference (P =.008). In patients with single-vessel disease (n = 10), defect sizes were smaller with quantification methods.

CONCLUSIONS

Quantification of Rb-82 net retention to measure the stress-rest perfusion difference in the myocardium defined a greater extent of disease than the standard approach in this group of patients with triple-vessel disease. More accurate measurement of the extent of coronary artery disease could facilitate better risk stratification and identify more high-risk patients in whom aggressive intervention is required.

Domoic acid, the alleged "mussel toxin," might produce its neurotoxic effect through kainate receptor activation: an electrophysiological study in the dorsal hippocampus

Domoic acid, an excitatory amino acid structurally related to kainate, was recently identified as being presumably responsible for the recent severe intoxication presented by more than 100 people having eaten mussels grown in Prince Edward Island (Canada). The amino acid kainate has been shown to be highly neurotoxic to the hippocampus, which is the most sensitive structure in the central nervous system. The present in vivo electrophysiological studies were undertaken to determine if domoic acid exerts its neurotoxic effect via kainate receptor activation. Unitary extracellular recordings were obtained from pyramidal neurons of the CA1 and the CA3 regions of the rat dorsal hippocampus. The excitatory effect of domoic acid applied by microiontophoresis was compared with that of agonists of the three subtypes of glutamatergic receptors: kainate, quisqualate, and N-methyl-D-aspartate. In CA1, the activation induced by domoic acid was about threefold greater than that induced by kainate; identical concentrations and similar currents were used. In CA3, domoic acid was also three times more potent than kainate. However, the most striking finding was that domoic acid, similar to kainate, was more than 20-fold more potent in the CA3 than in the CA1 region, whereas no such regional difference could be detected with quisqualate and N-methyl-D-aspartate. As the differential regional response of CA1 and CA3 pyramidal neurons to kainate is attributable to the extremely high density of kainate receptors in the CA3 region, these results provide the first electrophysiological evidence that domoic acid may produce its neurotoxic effects through kainate receptor activation.

[Drug abuse in youth.]

In an on-going review of the literature dealing with the assessment of drug abuse treatment and prevention programs, the authors indicate that changes are occurring in basic concepts : the concept of addiction has been expanded and a more systemic approach to drug use and abuse is more prevalent. An examination of the relationship between adolescent drug use and the related psychosocial images leads to an outline of two main evaluative approaches : the moralistic a priori approach and the empirical social approach. To efficiently prevent youthful drug abuse, they propose that primary preventive actions should focus on demand factors and be complemented with secondary preventive actions focused on supply factors.