The Potential Role of PET in the Management of Peripheral Artery Disease

PURPOSE OF REVIEW

Current non-invasive tests for evaluating patients with peripheral artery disease (PAD) have significant limitations for early detection and management of patients with PAD and are generally focused on the evaluation of large vessel disease. PAD often involves disease of microcirculation and altered metabolism. Therefore, there is a critical need for reliable quantitative non-invasive tools that can assess limb microvascular perfusion and function in the setting of PAD.

RECENT FINDINGS

Recent developments in positron emission tomography (PET) imaging have enabled the quantification of blood flow to the lower extremities, the assessment of the viability of skeletal muscles, and the evaluation of vascular inflammation and microcalcification and angiogenesis in the lower extremities. These unique capabilities differentiate PET imaging from current routine screening and imaging methods. The purpose of this review is to highlight the promising role of PET in the early detection and management of PAD providing a summary of the current preclinical and clinical research related to PET imaging in patients with PAD and related advancement of PET scanner technology.

Prognostic value of age-sex adjusted NT-proBNP ratio in obstructive hypertrophic cardiomyopathy

BACKGROUND

We sought to determine the incremental prognostic value of age-sex adjusted N-terminal prohormone brain natriuretic peptide (NT-pro BNP) ratio in obstructive hypertrophic cardiomyopathy (oHCM) patients.

METHODS

The study included 2119 consecutive oHCM patients (age 55 ± 13 years, 53% men, maximal LVOT ≥30 mmHg) evaluated between 6/2002-12/2018 with BNP or NT-pro BNP measured at baseline. NT-pro BNP ratio was calculated as: NT-proBNP/ upper limit of normal NT-proBNP derived from age-sex matched controls. Septal reduction therapy (SRT) during follow-up was recorded. Primary endpoint was death, need for cardiac transplantation or appropriate internal cardioverter defibrillator (ICD) discharge.

RESULTS

Median NT-proBNP ratio was 5.4 (IQR 2.1-12.3). Using spline analysis, log-transformed NT-pro BNP ratio of 2 (corresponding to NT-pro BNP ratio of 6) was the optimal value where primary endpoint hazards crossed 1; there were 966 patients with high and 1153 patients with low NT-pro BNP ratio. 1665 (79%) patients underwent SRT at 47 days (IQR 7-128 days). At 5.4 years of follow-up (IQR 2.8-9.2 years), the primary outcome occurred in 315 (15%) patients (deaths = 270). High NT-pro BNP ratio was associated with higher risk of primary outcome in unadjusted (30.1 vs. 17.2 events/1000 person-year, hazard ratio or (HR) 1.73, 1.37-2.17, P < 0.001) and adjusted analysis (aHR 1.69, 95% 1.19-2.38, P = 0.003) vs. low NT-pro BNP ratio. Even in asymptomatic patients, NT-pro BNP ratio remained associated with primary outcome (aHR 1.28, 95% CI 1.06-1.54, P = 0.01).

CONCLUSIONS

Age-sex adjusted NT-pro BNP ratio is independently associated with long-term outcomes in oHCM patients, including in a subgroup of asymptomatic patients.

The Enhanced Cardiac Outcome of Conjugated SGLT2 Inhibitors and GLP-1RA Therapy in Diabetic Patients

PURPOSE OF REVIEW

Cardiovascular disease secondary to diabetes continues to threaten the survivability of many people all over the world. We assess the most recent findings of synergistic effects of combined glucagon-like peptide 1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter 2 (SGLT2) inhibitors in lowering cardiac complications in the diabetic population. We describe drug therapies' mechanism of action, postulated cardioprotective process, the additive value of conjugated therapy, and analyze recently reported study and its limitation.

RECENT FINDINGS

SGLT2 inhibitors and GLP-1RAs have gained popularity due to their ability to reduce major adverse cardiovascular events in diabetic patients. There is emerging evidence of the additional cardiovascular benefit from the combined application of SGLT2 inhibitors and GLP-1RAs therapy demonstrated by a recent real-world cohort study. Reducing cardiac mortality in patients with diabetes by administering dual antihyperglycemic therapies (GLP-1Rs and SGLT2 inhibitors) might play a key role in the future treatment of the diabetic population.

Outcomes in Patients With Obstructive Hypertrophic Cardiomyopathy and Concomitant Aortic Stenosis Undergoing Surgical Myectomy and Aortic Valve Replacement

Background Hypertrophic cardiomyopathy (HCM) and aortic stenosis can cause obstruction to the flow of blood out of the left ventricular outflow tract into the aorta, with obstructive HCM resulting in dynamic left ventricular outflow tract obstruction and moderate or severe aortic stenosis causing fixed obstruction caused by calcific degeneration. We sought to report the characteristics and longer-term outcomes of patients with severe obstructive HCM who also had concomitant moderate or severe aortic stenosis requiring surgical myectomy and aortic valve replacement. Methods and Results We studied 191 consecutive patients (age 67±6 years, 52% men) who underwent myectomy and aortic valve (AV) replacement (90% bioprosthesis) at our center between June 2002 and June 2018. Clinical and echo data including left ventricular outflow tract gradient and indexed AV area were recorded. The primary outcome was death. Prevalence of hypertension (63%) and hyperlipidemia (75%) were high, with a Society of Thoracic Surgeons score of 5±4, and 70% of participants had no HCM-related sudden death risk factors. Basal septal thickness and indexed AV area were 1.9±0.4 cm and 0.72±0.2 cm²/m², respectively, while 100% of patients had dynamic left ventricular outflow tract gradient >50 mm Hg. At 6.5±4 years, 52 (27%) patients died (1.5% in-hospital deaths). One-, 2-, and 5-year survival in the current study sample was 94%, 91%, and 83%, respectively, similar to an age-sex-matched general US population. On multivariate Cox survival analysis, age (hazard ratio [HR], 1.65; 95% CI, 1.24-2.18), chronic kidney disease (HR, 1.58; 95% CI, 1.21-2.32), and right ventricular systolic pressure on preoperative echocardiography (HR, 1.28; 95% CI, 1.05-1.57) were associated with longer-term mortality, but traditional HCM risk factors did not. Conclusions In symptomatic patients with severely obstructive HCM and moderate or severe aortic stenosis undergoing a combined surgical myectomy and AV replacement at our center, the observed postoperative mortality was significantly lower than the expected mortality, and the longer-term survival was similar to a normal age-sex-matched US population.

Depressed right ventricular systolic function in heart failure due to constrictive pericarditis

Aims

Heart failure in constrictive pericarditis (CP) is attributed to impaired biventricular diastolic filling. However, diseases that cause CP due to myocardial infiltration and fibrosis can also impair biventricular systolic function (sf) and contribute to heart failure. This study of patients with CP examined biventricular sf and the effect of myocardial infiltration by pericardial diseases and the resulting fibrosis on ventricular sf.

Methods and results

Histopathologic examinations of right ventricular (RV) and left ventricular (LV) myocardia and pericardia were performed on three autopsied hearts of patients with pericardial diseases. Additionally, in 40 adults with clinical heart failure and 40 healthy adults (controls), sf of both ventricles was examined by echocardiography, including strain measurements, and biventricular diastolic filling and pulmonary artery pressures were assessed by cardiac catheterization. Cardiac histopathology indicated thickening of the pericardium with fibrosis, disease infiltrating the myocardium, greater infiltration of the RV than the LV, and an association of pericardial thickness with myocardial infiltrations. Functional analysis indicated that RVsf was impaired on all echo indices, including strain measurement, but LVsf was preserved.

Conclusions

Diseases causing CP are not restricted to the pericardium but also infiltrate the biventricular myocardium and affect the thin‐walled RV more than the thick‐walled LV, resulting in depressed RVsf. The present results help explain clinical heart failure in the presence of restricted diastolic filling in CP. Depression of RVsf due to progression of fibrosis in the RV myocardium may increase the risk of delayed pericardiectomy.

Characteristics and Longer-Term Outcomes of Contemporary Patients <18 Years of Age With Hypertrophic Cardiomyopathy

We describe characteristics and outcomes of contemporary pediatric hypertrophic cardiomyopathy (PHC) patients. We studied 398 consecutive pediatric HC patients (<18 years, median 14 years, 65% boys) seen at our center between 2002 and 2018. Baseline clinical and pediatric echocardiographic data was collected. Left ventricular outflow tract gradient (LVOTG), LV fractional shortening and Z-score for left ventricular (LV) wall thickness were calculated. Sudden cardiac death (SCD), appropriate internal defibrillator discharge (ICD), myectomy, and orthotopic heart transplant (OHT) were composite primary endpoint. A total of 133 (33%) had symptoms (71 [18%] dyspnea, 77 [19%] angina, and 19 [5%] syncope), 109 (27%) were on beta-blockers; 179 (45%) had family history of HC. A total of 146 (37%) underwent genetic testing (of which 91 (62%) were HC-gene positive). Basal septal LV thickness, septal LV z-score and fractional shortening were 1.2 ± 0.6 cm, 4.8 ± 5.6, and 42% ± 8, whereas 23% had extreme LV hypertrophy (z-score > 6) and 8% had LVOTG >30 mm Hg (range 0 to 139 mm Hg). At a median of 5.9 years (interquartile range 2.4, 9), there were 23 (6%) ICD's placed, and 47 (12%) primary composite events (9 [2%] deaths, 3 [1%] appropriate ICD discharge, 29 [7%] myectomy, and 8 [2%] OHT). There were no in hospital deaths following myectomy/OHT. Presence of symptoms (Hazard ratio or HR 2.45), ventricular tachycardia (HR 1.52), and higher basal septal LV z-score (HR 1.10) were independently associated with primary composite outcomes. LV septal z-score >4 was independently associated with events on spline analysis. Rate of SCD/appropriate ICD discharge was 0.5%/year. In conclusion, contemporary PHC patients seen at an experienced center have excellent outcomes with presence of symptoms and higher LV septal thickness associated with primary composite events.

Characteristics and Outcomes of Elderly Patients With Hypertrophic Cardiomyopathy

Background

We report characteristics and outcomes of elderly patients with hypertrophic cardiomyopathy (HCM) with basal septal hypertrophy and dynamic left ventricular outflow tract obstruction.

Methods and Results

We studied 1110 consecutive elderly patients with HCM (excluding moderate or greater aortic stenosis or subaortic membrane, age 80±5 years [range, 75–92 years], 66% women), evaluated at our center between June 2002 and December 2018. Clinical and echocardiographic data, including maximal left ventricular outflow tract gradient, were recorded. The primary outcome was death and appropriate internal defibrillator discharge. Hypertension was observed in 72%, with a Society of Thoracic Surgeons (STS) score (8.6±6); while 80% had no HCM‐related sudden cardiac death risk factors. Left ventricular mass index, basal septal thickness, and maximal left ventricular outflow tract gradient were 127±43 g/m², 1.7±0.4 cm, and 49±31 mm Hg, respectively. A total of 597 (54%) had a left ventricular outflow tract gradient >30 mm Hg, of which 195 (33%) underwent septal reduction therapy (SRT; 79% myectomy and 21% alcohol ablation). At 5.1±4 years, 556 (50%) had composite events (273 [53%] in nonobstructive, 220 [55%] in obstructive without SRT, and 63 [32%] in obstructive subgroup with SRT). One‐ and 5‐year survival, respectively were 93% and 63% in nonobstructive, 90% and 63% in obstructive subgroup without SRT, and 94% and 84% in the obstructive subgroup with SRT. Following SRT, there were 5 (2.5%) in‐hospital deaths (versus an expected Society of Thoracic Surgeons mortality of 9.2%).

Conclusions

Elderly patients with HCM have a high prevalence of traditional cardiovascular rather than HCM risk factors. Longer‐term outcomes of the obstructive SRT subgroup were similar to a normal age‐sex matched US population.

Outcomes in Guideline-Based Class I Indication Versus Earlier Referral for Surgical Myectomy in Hypertrophic Obstructive Cardiomyopathy

Background

In patients with obstructive hypertrophic cardiomyopathy, surgical myectomy (SM) is indicated for severe symptoms. We sought to compare long‐term outcomes of patients with obstructive hypertrophic cardiomyopathy where SM was based on guideline‐recommended Class I indication (Functional Class or FC ≥3 or angina/exertional syncope despite maximal medical therapy) versus earlier (FC 2 and/or impaired exercise capacity on exercise echocardiography with severe obstruction).

Methods and Results

We studied 2268 consecutive patients (excluding <18 years, ≥ moderate aortic stenosis and subaortic membrane, 56±14 years, 55% men), who underwent SM at our center between June 2002 and March 2018. Clinical data, including left ventricular outflow tract gradient, were recorded. Death and/or appropriate internal defibrillator discharge were primary composite end points. One thousand three hundred eighteen (58%) patients met Class I indication and 950 (42%) underwent earlier surgery; 222 (10%) had a history of obstructive coronary artery disease. Basal septal thickness, and resting and maximal left ventricular outflow tract gradient were 2.0±0.3 cm, 61±44 mm Hg, and 100±31 mm Hg, respectively. At 6.2±4 years after SM, 248 (11%) had composite events (13 [0.6%] in‐hospital deaths). Age (hazard ratio [HR], 1.61; 95% CI, 1.26–1.91), obstructive coronary artery disease (HR, 1.46; 95% CI, 1.06–1.91), and Class I versus earlier SM (HR, 1.61; 95% CI, 1.14–2.12) were associated with higher primary composite events (all P<0.001). Earlier surgery had better longer‐term survival (similar to age‐sex‐matched normal population) versus surgery for Class I indication (76 [8%] versus 193 [15%], P<0.001).

Conclusions

In patients with obstructive hypertrophic cardiomyopathy, earlier versus surgery for Class I indication had a better long‐term survival, similar to the age‐sex‐matched US population.

Diastolic stress test echocardiography in patients with hypertrophy cardiomyopathy: association with exercise capacity

Background

Diastolic dysfunction (DD) is a frequent occurrence in hypertrophic cardiomyopathy (HCM) patients. Symptoms of DD are often unmasked only during exercise, as left ventricular (LV) filling pressure is normal at rest.

Purpose

We sought to establish if abnormal DST parameters are associated with reduced exercise capacity in HCM patients.

Methods

We examined 590 asymptomatic/minimally symptomatic HCM patients (54±14 years, 57% men, body mass index 30±6 kg/m2, 84% on beta-blockers) with HCM by echocardiography at rest & maximal exercise. Septal and lateral [e'] mitral annular velocity, peak early [E] and late [A] mitral inflow velocity, Mitral E/e' and left atrial volume index (LAVI) was recorded. Exercise functional capacity was stablished as age-gender predicted metabolic equivalents (AGP-METs).

Results

Echocardiography at rest had LVEF of 62±6, wall thickness of 16.7±0.5 mm, LVMI of 111±43 g m–2, LVOT gradient of 26±33 mmHg, LAVI 34.5±17 mm, E/A ratio of 1.2±0.6, and average E/e' ratio 12.7±0.6. Following maximal exercise had a mean LVOT gradient of 61±59 mmHg, E/A ratio of 1.2±1.0 and average E/e' ratio 12.7±1.0. Only 42% had &gt;85% of age-sex predicted METs. Logistic regression analysis testing the association between various predictors and 85% AGP-METs are shown in table 1.

Conclusion

There is a significant association between abnormal diastolic response to exercise and reduced exercise capacity in patients with HCM.

Funding Acknowledgement

Type of funding source: None

Exercise capacity is associated with rest and peak-exercise left ventricular global longitudinal strain in patients with hypertrophic cardiomyopathy

Background

Patients with hypertrophic cardiomyopathy (HCM) frequently have reduced exercise capacity, which can be associated with subclinical cardiac dysfunction. Left ventricle global myocardial strain (LV-GLS) is a sensitive index to detect subclinical myocardial dysfunction. However, the clinical utility of LV-GLS during exercise test remains uncertain.

Purpose

We assessed the association of functional capacity with LV-GLS at rest and at the peak of stress in HCM patients.

Methods

We examined 566 asymptomatic/minimally symptomatic HCM patients (54±14 years, 57% men, body mass index 30±6 kg/m2, 84% on beta-blockers) by echo at rest and following maximal exercise. We recorded clinical, echo variables (LV ejection fraction [LVEF], LV thickness, left ventricle mass index [LVMI], left ventricle outflow tract [LVOT] gradient, LV-GLS at rest and at peak stress), and exercise variables (percent of age-gender predicted metabolic equivalents [AGP-METs]).

Results

Echo parameters were as follows: LVEF at rest of 62±6%, wall thickness of 16.9±0.4 mm, LVMI of 117±47 g/m2, LVOT gradient at rest of 27±33 mmHg, LV-GLS at rest of −15.9±3.6%, LV-GLS at peak of stress of −17.4±4.3%, and change in LV strain from rest to stress of −1.9±2.3%. Only 41% of patients achieved &gt;85% of AGP-METs. Logistic regression demonstrating an association between AGP-METs less than 85% and various predictors are shown in Table 1.

Conclusion

Impaired deformation at peak of stress assessed by LV-GLS was associated with reduced exercise capacity measured as AGP-METs less than 85%. These findings suggest that early systolic cardiac deterioration should be considered as a cause of exercise impairment in patients with HCM.

Funding Acknowledgement

Type of funding source: None

A novel arterial redox-specific machine learning-derived radiomic signature of perivascular adipose tissue predicts cardiac mortality from routine CCTA

Background

Vascular oxidative stress is involved in inflammation and atherogenesis. Vascular inflammation induces spatial changes in perivascular adipose tissue (PVAT) composition, which can be detected by radiomic analysis of coronary computed tomography angiography (CCTA) images.

Purpose

To explore the association of arterial oxidative stress with long-term risk of major adverse cardiovascular events (MACE). To develop a radiomic signature to identify high oxidative stress non-invasively using CCTA. Finally, to assess the ability of this signature to predict future cardiac risk.

Methods

Arm 1 included 272 patients undergoing cardiac surgery. Segments of internal mammary artery (IMA) were used for ex-vivo quantification of NADPH-stimulated and Vas2870 (pan-NOX inhibitor) inhibitable superoxide production by lucigenin-enhanced chemiluminescence. Eighty-two of these patients with CCTA scans available constituted Arm 2. Peri-IMA PVAT was segmented and used to extract 1,616 radiomic features, which, after filtering (40 final features), were utilised to train extreme gradient boosting, a machine learning algorithm, to predict high arterial oxidative stress. Arm 3 included a nested cohort of 308 participants (41 suffering cardiac death and 267 matched controls) from the CRISP-CT (Cardiovascular RISk Prediction using Computed Tomography) study to externally validate the redox-specific signature developed in Arm 2 for cardiac risk prediction.

Results

Over a median follow-up of 40 months, 18 (6.6%) MACE (cardiovascular death, non-fatal myocardial infarction, and stroke) occurred in Arm 1. High arterial NADPH-stimulated superoxide was independently associated with MACE risk (Adj. HR[95% CI]: 1.61 [1.04–2.53] per SD, p=0.03, adjusted for age, sex, diabetes, hypertension, hyperlipidemia, smoking, obesity, and plasma TNFa). Unsupervised hierarchical clustering of radiomic features from peri-IMA PVAT segments in Arm 2 identified two distinct clusters (A) that differed in NADPH stimulated (p=0.01) and Vas2870 inhibitable (p=0.04) IMA superoxide (B), supporting the hypothesis that PVAT mapping can capture changes corresponding to differential levels of underlying vascular redox state. This prompted the development of a radiomic signature specific to PVAT alterations associated with high vascular oxidative stress, which was validated in Arm 3 (AUC:0.61, p=0.026, C). The novel signature was able to stratify cardiac risk in the validation set, independently of the Fat Attenuation Index, epicardial adipose tissue volume, high-risk plaque features, and obstructive CAD (Adj. HR [95% CI]:2.56 [1.35–4.87], p=0.004, D).

Conclusion

Increased arterial oxidative stress predicts cardiac risk in patients with advanced atherosclerosis. We present for the first time a novel, non-invasive CCTA imaging biomarker reflecting changes in vascular redox state by radiomic phenotyping of perivascular space, which stratifies cardiac risk beyond standard and newer risk assessment methods.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): British Heart Foundation, National Institute of Health Research, Oxford Biomedical Research Centre

Characteristics and Outcomes of Patients With Takotsubo Syndrome: Incremental Prognostic Value of Baseline Left Ventricular Systolic Function

Background

We sought to determine (1) long‐term outcomes in patients presenting with documented Takotsubo syndrome (TS), (2) whether left ventricular global longitudinal strain (LV‐GLS) provides incremental prognostic value, and (3) prognostic cutoffs of LV ejection fraction (LVEF) and LV‐GLS during an acute TS episode.

Methods and Results

We studied 650 patients with TS (aged 66±14 years, 88% women) who were diagnosed clinically and angiographically between 2006 and 2018. Baseline LVEF and LV‐GLS (using velocity vector imaging) were recorded. The primary end point was all‐cause mortality. TS triggers were unknown (34%), emotional (16%), physical (41%), and neurologic (10%). Mean LVEF and LV‐GLS were 36±10% and −11.6±0.4%; in addition, 94% patients had LVEF <52%, and 80% had apical ballooning. No patient had obstructive coronary artery disease. At a median of 2.2 years (interquartile range, 0.7–4.4), 175 (27%) had died (9% in‐hospital deaths). Multivariate Cox survival analysis revealed that higher age (hazard ratio [HR], 1.35), male sex (HR, 1.75), lower baseline LVEF (HR, 1.02), worse LV‐GLS (HR, 1.04), neurologic trigger (HR, 2.66), and physical trigger (HR, 2.64) were associated with mortality, whereas aspirin (HR, 0.70) and β‐blockers (HR, 0.73) improved survival (all P<0.049). The addition of LVEF and LV‐GLS to clinical markers (age, sex, cardiogenic shock at presentation, and peak troponin I) significantly increased log‐likelihood ratios: clinical (−521.48), clinical plus LVEF (−511.32, P<0.001), and clinical plus LVEF and LV‐GLS (−500.68, P<0.001). On penalized spline analysis, LVEF of 38% and LV‐GLS of −10% were cutoffs below which survival was significantly worse.

Conclusions

Patients with TS with a neurologic or physical trigger had significantly worse survival than those without such a trigger, with baseline LVEF and LV‐GLS providing incremental prognostic value.

Erratum to accuracy of wearable heart rate monitors in cardiac rehabilitation

[This corrects the article DOI: 10.21037/cdt.2019.04.08.].

Global, Regional, and National Burden of Calcific Aortic Valve and Degenerative Mitral Valve Diseases, 1990-2017

BACKGROUND

Nonrheumatic valvular diseases are common; however, no studies have estimated their global or national burden. As part of the Global Burden of Disease Study 2017, mortality, prevalence, and disability-adjusted life-years (DALYs) for calcific aortic valve disease (CAVD), degenerative mitral valve disease, and other nonrheumatic valvular diseases were estimated for 195 countries and territories from 1990 to 2017.

METHODS

Vital registration data, epidemiologic survey data, and administrative hospital data were used to estimate disease burden using the Global Burden of Disease Study modeling framework, which ensures comparability across locations. Geospatial statistical methods were used to estimate disease for all countries, because data on nonrheumatic valvular diseases are extremely limited for some regions of the world, such as Sub-Saharan Africa and South Asia. Results accounted for estimated level of disease severity as well as the estimated availability of valve repair or replacement procedures. DALYs and other measures of health-related burden were generated for both sexes and each 5-year age group, location, and year from 1990 to 2017.

RESULTS

Globally, CAVD and degenerative mitral valve disease caused 102 700 (95% uncertainty interval [UI], 82 700-107 900) and 35 700 (95% UI, 30 500-42 500) deaths, and 12.6 million (95% UI, 11.4 million-13.8 million) and 18.1 million (95% UI, 17.6 million-18.6 million) prevalent cases existed in 2017, respectively. A total of 2.5 million (95% UI, 2.3 million-2.8 million) DALYs were estimated as caused by nonrheumatic valvular diseases globally, representing 0.10% (95% UI, 0.09%-0.11%) of total lost health from all diseases in 2017. The number of DALYs increased for CAVD and degenerative mitral valve disease between 1990 and 2017 by 101% (95% UI, 79%-117%) and 35% (95% UI, 23%-47%), respectively. There is significant geographic variation in the prevalence, mortality rate, and overall burden of these diseases, with highest age-standardized DALY rates of CAVD estimated for high-income countries.

CONCLUSIONS

These global and national estimates demonstrate that CAVD and degenerative mitral valve disease are important causes of disease burden among older adults. Efforts to clarify modifiable risk factors and improve access to valve interventions are necessary if progress is to be made toward reducing, and eventually eliminating, the burden of these highly treatable diseases.

A novel machine learning-derived radiotranscriptomic signature of perivascular fat improves cardiac risk prediction using coronary CT angiography

BACKGROUND

Coronary inflammation induces dynamic changes in the balance between water and lipid content in perivascular adipose tissue (PVAT), as captured by perivascular Fat Attenuation Index (FAI) in standard coronary CT angiography (CCTA). However, inflammation is not the only process involved in atherogenesis and we hypothesized that additional radiomic signatures of adverse fibrotic and microvascular PVAT remodelling, may further improve cardiac risk prediction.

METHODS AND RESULTS

We present a new artificial intelligence-powered method to predict cardiac risk by analysing the radiomic profile of coronary PVAT, developed and validated in patient cohorts acquired in three different studies. In Study 1, adipose tissue biopsies were obtained from 167 patients undergoing cardiac surgery, and the expression of genes representing inflammation, fibrosis and vascularity was linked with the radiomic features extracted from tissue CT images. Adipose tissue wavelet-transformed mean attenuation (captured by FAI) was the most sensitive radiomic feature in describing tissue inflammation (TNFA expression), while features of radiomic texture were related to adipose tissue fibrosis (COL1A1 expression) and vascularity (CD31 expression). In Study 2, we analysed 1391 coronary PVAT radiomic features in 101 patients who experienced major adverse cardiac events (MACE) within 5 years of having a CCTA and 101 matched controls, training and validating a machine learning (random forest) algorithm (fat radiomic profile, FRP) to discriminate cases from controls (C-statistic 0.77 [95%CI: 0.62-0.93] in the external validation set). The coronary FRP signature was then tested in 1575 consecutive eligible participants in the SCOT-HEART trial, where it significantly improved MACE prediction beyond traditional risk stratification that included risk factors, coronary calcium score, coronary stenosis, and high-risk plaque features on CCTA (Δ[C-statistic] = 0.126, P < 0.001). In Study 3, FRP was significantly higher in 44 patients presenting with acute myocardial infarction compared with 44 matched controls, but unlike FAI, remained unchanged 6 months after the index event, confirming that FRP detects persistent PVAT changes not captured by FAI.

CONCLUSION

The CCTA-based radiomic profiling of coronary artery PVAT detects perivascular structural remodelling associated with coronary artery disease, beyond inflammation. A new artificial intelligence (AI)-powered imaging biomarker (FRP) leads to a striking improvement of cardiac risk prediction over and above the current state-of-the-art.

3258Perivascular fat attenuation index stratifies the cardiac risk associated with high-risk plaque features on coronary computed tomography angiography

Background

Qualitative high-risk plaque (HRP) features detected on coronary computed tomography angiography (CCTA) are associated with increased risk of adverse cardiac events. Coronary inflammation is a key determinant of plaque progression and instability and can now be captured on routine CCTA as inflammation-induced changes in perivascular adipose tissue composition, detectable by the perivascular Fat Attenuation Index (FAI).

Purpose

To explore the ability of perivascular FAI phenotyping to stratify the cardiac risk associated with the presence of adverse plaque morphology on routine CCTA.

Methods

This was a post-hoc analysis of the CRISP-CT (Cardiovascular RISk Prediction using Computed Tomography) study, which involved 3912 patients (mean age 55.7±13.7 years, 41.1% females) undergoing clinically-indicated CCTA in two centres (Erlangen, Germany & Cleveland, USA). Perivascular FAI mapping was performed around the proximal 10–50 mm of the right coronary artery and defined as the weighted mean attenuation of the perivascular adipose tissue, as previously validated. HRP features were defined as the presence of ≥1 of the following: positive remodelling, low-attenuation plaque, spotty calcification or napkin-ring sign (A). Cox regression models (adjusted for age, sex, epicardial fat volume and coronary artery disease [≥50% stenosis]) were used to explore the association between FAI, HRP, and future major adverse cardiac events (MACE: defined as the composite of cardiac mortality and non-fatal myocardial infarction).

Results

At baseline the prevalence of HRP and high FAI (≥-70.1 Hounsfield Units, as previously validated) was 23.6% (n=923) and 24.3% (n=952) respectively. Over a median follow-up period of 5.6 years (25th-75th percentile: 4.0–7.0 years) there were 91 confirmed MACE. Patients with both HRP features (HRP+) and high FAI (FAI+) had a 6.3-fold (P<0.001) higher adjusted risk of MACE compared to individuals with neither of these risk features (HRP-/FAI-) (B). Furthermore, patients without HRP features but with high FAI (HRP-/FAI+) had a 4.9-fold (P<0.001) higher adjusted risk of MACE compared to the reference (HRP-/FAI-) group. However, among patients with low FAI, there was no significant difference in the prospective risk of MACE between HRP+ and HRP- patients (P=0.87).

Conclusion

FAI is associated with an increased risk of adverse events in both patients with and without high-risk plaques, highlighting coronary inflammation as a major determinant of plaque vulnerability, independent of adverse plaque morphology. Non-invasive characterization of coronary inflammation using CCTA-derived FAI can improve risk stratification by supplementing the traditional anatomical assessment of the coronary vasculature with a functional marker of disease activity.

Acknowledgement/Funding

British Heart Foundation, National Institute of Health Research, Oxford Biomedical Research Centre

P1951Serial left ventricular global longitudinal strain and mortality in patients with Takotsubo cardiomyopathy

Background

Recent studies on Takotsubo cardiomyopathy (TC) have challenged the common conception that it is a relatively benign condition with functional recovery observed in the majority of cases. However, it is important to recognize that overt functional recovery might not reflect the true regional recovery, which might have an adverse impact on survival.

Objective

We sought to assess baseline and follow-up left ventricular function characteristics and their impact on longer-term mortality in patients presenting with documented Takotsubo cardiomyopathy (TC) at a tertiary centre.

Methods

339 patients (66±14 years, 88% women) presented to our centre between 2006 and 2018 with acute anginal symptoms and were subsequently diagnosed with TC following clinical and angiographic evaluation. All patients returned for a follow-up evaluation including transthoracic echocardiography (TTE). Baseline and follow-up (3–6 months after TC diagnosis) LV ejection fraction (LVEF) and LV global longitudinal strain (LV-GLS using velocity vector imaging) were recorded on TTE. The primary endpoint was longer-term mortality.

Results

Hypertension, dyslipidaemia, and diabetes were present in 71%, 56%, and 26% of patients. Baseline mean troponin I peak, LVEF and LV-GLS were 0.9±7 ng/ml, 36±9%, and 11±3%; respectively. 94% had baseline LVEF<50%, 272 (80%) had apical ballooning, and 94% had LV-GLS worse than −18%. No patient had angiographically obstructive coronary artery disease. At 3–6 months follow-up, mean LVEF, and LV-GLS improved to 57±9% and 16±3%, respectively. 87% of patients had LVEF >50%, but in 70% LV-GLS remained worse than −18%. After 3.3±3 years, 72 patients (21%) died. On multivariable Cox survival analysis (adjusted for age, gender, baseline troponin peak and follow up LVEF), follow up LV-GLS was independently associated with longer-term mortality (hazard ratio 1.12 [95% confidence interval 1.05, 1.20], p<0.001). Significantly more patients with follow up LV-GLS worse than −18% died vs. those with LV-GLS better than −18% (57/237 [24%] vs. 15/102 [15%], log-rank statistic p-value 0.01, Kaplan-Meier figure 1).

Kaplan-Meier curve of freedom from death

Conclusions

In this large single-centre study of patients with documented TC (majority women), 87% recovered LVEF at 3–6 months, but in 70% LV-GLS remained worse than −18%, which was independently associated with higher longer-term mortality.

226Earlier surgical myectomy vs. waiting for a Class I indication is associated with improved long-term survival in symptomatic hypertrophic obstructive cardiomyopathy patients

Background

In patients with severe hypertrophic obstructive cardiomyopathy (HOCM), surgical myectomy (SM) is typically indicated for severe symptoms despite maximal medical therapy.

Aims

We sought to compare long-term outcomes of severe HOCM patients where decision for SM was based on guideline-recommended Class I indication (functional Class or FC ≥3 or exertional syncope despite maximal medical therapy) vs. earlier (FC II and/or impaired exercise capacity on exercise echo with medication intolerance).

Methods

The study included 2268 HOCM patients (excluding <18 years, at least moderate aortic stenosis requiring valve replacement and subaortic membrane, age 56±14 years, 55% men), who underwent SM at our center between 1/02–3/18. Clinical and echo data, including left ventricular outflow tract gradient (LVOTG) were recorded. Cardiac death and/or appropriate internal defibrillator discharge were recorded as composite endpoints.

Results

1318 (58%) patients met Class I indication for SM, while the rest underwent SM for FC II (due to medicine intolerance) or impaired exercise capacity. 535 (24%) and 408 (18%) had history of atrial fibrillation and a family history of HCM. All patients were on maximally tolerated medical therapy. European 5-year sudden death risk score was 3.7±2%. Baseline basal septal thickness, resting and maximal LVOTG were 2.0±0.3 cm, 61±44 mm Hg and 100±31 mm Hg. At 6.2±4 years of follow-up after SM, 248 (11%) had composite events (13 [0.6%] in-hospital deaths). Competing risk survival analysis for composite endpoint is shown in Figure 1a. Patients operated for Class I indication had significantly higher longer-term event rate vs. those operated earlier (182 [14%] vs. 66 [7%], p<0.001, Figure 1B).

Conclusions

In patients with severe HOCM undergoing SM at an experienced center performed by experienced surgeons, delaying surgery till reaching Class I indication was associated with much worse survival than operating earlier for milder symptoms or impaired exercise tolerance on exercise echo.

P6152Incremental prognostic utility of functionally non-significant coronary stenosis in patients undergoing coronary computed tomogram angiography

Background

In patients with suspected coronary artery disease (CAD) who underwent coronary computed tomographic angiography (CCTA), the prognostic value of nonobstructive stenosis is not entirely understood.

Aims

We sought to assess the long-term incremental prognostic utility of functionally non-significant CAD in patients without known prior CAD who underwent CCTA.

Methods

We included 2142 consecutive patients (51±14 years, 53% men) without prior documented CAD who underwent CCTA between 2008–2016 (excluding anomalous coronaries and functionally significant CAD). Traditional risk factors were recorded and pretest likelihood of CAD was calculated. All epicardial coronary arteries were classified as follows: No plaque, minimal luminal irregularities (<25%), mild (25–49%) stenosis and moderate (50–69%) stenosis. All moderate stenoses were confirmed to be not functionally significant by follow-up stress testing/invasive angiography with fractional flow reserve assessment. Plaque was characterized as noncalcified, calcified or mixed. High-risk plaque features (spotty calcification, napkin ring, low attenuation plaque and positive remodeling) were recorded. During follow-up, a composite of death or myocardial infarction was recorded.

Results

188 (9%) patients had low, 1712 (80%) had intermediate and 242 (11%) patients had high pre-test likelihood of CAD. 45%, 10%, 52% and 22% had hypertension, diabetes, Dyslipedimia and history of smoking respectively. Breakdown of CAD severity was: 1197 (56%) none, 480 (22%) minimal, 267 (13%) mild and 198 (9%) moderate stenoses. 82 (4%) had noncalcified, 245 (11%) had calcified and 618 (29%) had mixed plaque. 465 (22%) had high-risk plaque features. At 6±3 years, 90 (4%) patients had composite events (68 deaths) and 24 (1%) needed coronary revascularization >90 days post-CCTA. 880 (41%) were on statins post-CCTA. Results of multivariable Cox Survival Analysis are shown in Figure 1A. Kaplan-Meier survival curves for a) more severe CAD and b) high-risk plaque features (vs. not) are shown in Figure 1B and C. Longer-term event rates for increasing CAD were 2.8%, 4.6%, 6% and 9.6%, respectively.

Conclusion

In mostly low/intermediate risk patients without documented CAD who underwent CCTA, a higher burden of nonobstructive coronary plaque (or presence of high-risk features) provide incremental prognostic value. Initiating statin therapy following detection of plaque on CCTA was associated with improved longer-term freedom from composite events.

Reclassification of coronary heart disease risk in a primary prevention setting: traditional risk factor assessment vs. coronary artery calcium scoring

Background

In a primary prevention screening program of asymptomatic middle-aged subjects, we sought to assess the degree of risk-reclassification provided by traditional risk assessment vs. coronary artery calcification scoring (CACS).

Methods

A total of 1,806 consecutive asymptomatic subjects (age 55 years, 76% men), who underwent comprehensive screening in a primary prevention clinic between 3/2016 and 9/2017 were included. Standard risk factors, C-reactive protein (CRP) and CAC scoring were performed. % 10-year coronary heart disease (CHD) risk was calculated using Reynolds Risk Score (RRS), atherosclerotic cardiovascular disease (ASCVD) score and multiethnic study on subclinical atherosclerosis (MESA) CACS were calculated. % 10-year CHD risk for all scores was categorized as follows: <1%, 1-5%, 6-10% and >10%.

Results

Mean CRP, RRS, ASCVD and MESA-CACS were 2.1±4.2, 3.7±4, 4.9±6, 4.9±5; 54% had CAC of 0, while 21% had CAC >75th percentile. There was a significant, but modest correlation between MESA-CAC score and (I) RRS (r=0.62) and (II) ASCVD scores (r=0.65, both P<0.001). Compared to MESA-CAC, for RRS, (I) 188 (10%) patients had a downgrade in risk and (II) 538 (30%) patients had an upgrade in risk (40% reclassification of risk). Similarly, compared to MESA-CAC, for ASCVD score, (I) 412 (23%) patients had a downgrade in risk and (II) 329 (18%) patients had a downgrade in risk (41% reclassification of risk).

Conclusions

In a primary prevention screening program of asymptomatic middle-aged patients, RRS overestimates and ASCVHD underestimates 10-year CHD risk vs. MESA-CACS. Addition of CACS results in significant risk reclassification.

Characteristics and Outcomes in a Contemporary Group of Patients With Suspected Significant Mitral Stenosis Undergoing Treadmill Stress Echocardiography

Background:

In contemporary patients with suspected significant mitral stenosis (MS) undergoing rest and treadmill stress echocardiography, we assessed characteristics and factors associated with longer-term survival.

Methods:

We studied 515 consecutive patients (asymptomatic/atypical symptoms, mean left ventricular ejection fraction 58±2%; 43% male) with suspected at least moderate MS ([1] native mitral valve [MV]: resting mean MV gradient ≥5 mm Hg or area ≤1.5 cm 2 and [2] prosthetic valve: resting mean MV gradient ≥5 mm Hg or effective orifice area ≤2 cm) who underwent rest and treadmill stress echocardiography between 1/2003 and 12/2013. MS was categorized as rheumatic (n=170, 33%), postsurgical (prior mitral repair/replacement, n=245, 48%), and primary nonrheumatic (n=100, 19%). Primary outcome was all-cause mortality.

Results:

Mean resting MV gradient and right ventricular systolic pressure were 8.5±3 and 39±13 mm Hg. Patients achieved 95±29% age-sex predicted metabolic equivalents; peak-stress MV gradient and right ventricular systolic pressure were 17±7 and 61±14 mm Hg, respectively. At 54 days (median), 224 (44%) underwent invasive mitral procedure. At 6±4 years, 76 (15%) died. On survival analysis, primary nonrheumatic MS (hazard ratio [HR], 4.92), higher Society of Thoracic Surgeons score (HR, 1.92), lower % age-sex predicted metabolic equivalents (HR, 1.22), and higher peak-stress right ventricular systolic pressure (HR, 1.35), was associated with higher mortality, while invasive mitral procedures were associated with improved survival (HR, 0.67; all P <0.01).

Conclusions:

In asymptomatic patients (or with atypical symptoms) with significant MS undergoing treadmill stress echocardiography, higher mortality was associated with primary nonrheumatic MS, lower % age-sex predicted metabolic equivalents, and higher peak-stress right ventricular systolic pressure, while invasive MV procedures were associated with survival.

Accuracy of wearable heart rate monitors in cardiac rehabilitation

Background

To assess the accuracy of four wearable heart rate (HR) monitors in patients with established cardiovascular disease enrolled in phase II or III cardiac rehabilitation (CR).

Methods

Eighty adult patients enrolled in phase II or III CR were monitored during a CR session that included exercise on a treadmill and/or stationary cycle. Participants underwent HR monitoring with standard ECG limb leads, an electrocardiographic (ECG) chest strap monitor (Polar H7), and two randomly assigned wrist-worn HR monitors (Apple Watch, Fitbit Blaze, Garmin Forerunner 235, TomTom Spark Cardio), one on each wrist. HR was recorded at rest and at 3, 5, and 7 minutes of steady-state exercise on the treadmill and stationary cycle.

Results

Across all exercise conditions, the chest strap monitor (Polar H7) had the best agreement with ECG (r_c=0.99) followed by the Apple Watch (r_c=0.80), Fitbit Blaze (r_c=0.78), TomTom Spark (r_c=0.76) and Garmin Forerunner (r_c=0.52). There was variability in accuracy under different exercise conditions. On the treadmill, only the Fitbit Blaze performed well (r_c=0.76), while on the stationary cycle, Apple Watch (r_c=0.89) and TomTom Spark (r_c=0.85) were most accurate.

Conclusions

In cardiac patients, the accuracy of wearable, optically based HR monitors varies, and none of those tested was as accurate as an electrode-containing chest monitor. This observation has implications for in-home CR, as electrode-containing chest monitors should be used when accurate HR measurement is imperative.

Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND

The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017) includes a comprehensive assessment of incidence, prevalence, and years lived with disability (YLDs) for 354 causes in 195 countries and territories from 1990 to 2017. Previous GBD studies have shown how the decline of mortality rates from 1990 to 2016 has led to an increase in life expectancy, an ageing global population, and an expansion of the non-fatal burden of disease and injury. These studies have also shown how a substantial portion of the world's population experiences non-fatal health loss with considerable heterogeneity among different causes, locations, ages, and sexes. Ongoing objectives of the GBD study include increasing the level of estimation detail, improving analytical strategies, and increasing the amount of high-quality data.

METHODS

We estimated incidence and prevalence for 354 diseases and injuries and 3484 sequelae. We used an updated and extensive body of literature studies, survey data, surveillance data, inpatient admission records, outpatient visit records, and health insurance claims, and additionally used results from cause of death models to inform estimates using a total of 68 781 data sources. Newly available clinical data from India, Iran, Japan, Jordan, Nepal, China, Brazil, Norway, and Italy were incorporated, as well as updated claims data from the USA and new claims data from Taiwan (province of China) and Singapore. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between rates of incidence, prevalence, remission, and cause of death for each condition. YLDs were estimated as the product of a prevalence estimate and a disability weight for health states of each mutually exclusive sequela, adjusted for comorbidity. We updated the Socio-demographic Index (SDI), a summary development indicator of income per capita, years of schooling, and total fertility rate. Additionally, we calculated differences between male and female YLDs to identify divergent trends across sexes. GBD 2017 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting.

FINDINGS

Globally, for females, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and haemoglobinopathies and haemolytic anaemias in both 1990 and 2017. For males, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and tuberculosis including latent tuberculosis infection in both 1990 and 2017. In terms of YLDs, low back pain, headache disorders, and dietary iron deficiency were the leading Level 3 causes of YLD counts in 1990, whereas low back pain, headache disorders, and depressive disorders were the leading causes in 2017 for both sexes combined. All-cause age-standardised YLD rates decreased by 3·9% (95% uncertainty interval [UI] 3·1-4·6) from 1990 to 2017; however, the all-age YLD rate increased by 7·2% (6·0-8·4) while the total sum of global YLDs increased from 562 million (421-723) to 853 million (642-1100). The increases for males and females were similar, with increases in all-age YLD rates of 7·9% (6·6-9·2) for males and 6·5% (5·4-7·7) for females. We found significant differences between males and females in terms of age-standardised prevalence estimates for multiple causes. The causes with the greatest relative differences between sexes in 2017 included substance use disorders (3018 cases [95% UI 2782-3252] per 100 000 in males vs s1400 [1279-1524] per 100 000 in females), transport injuries (3322 [3082-3583] vs 2336 [2154-2535]), and self-harm and interpersonal violence (3265 [2943-3630] vs 5643 [5057-6302]).

INTERPRETATION

Global all-cause age-standardised YLD rates have improved only slightly over a period spanning nearly three decades. However, the magnitude of the non-fatal disease burden has expanded globally, with increasing numbers of people who have a wide spectrum of conditions. A subset of conditions has remained globally pervasive since 1990, whereas other conditions have displayed more dynamic trends, with different ages, sexes, and geographies across the globe experiencing varying burdens and trends of health loss. This study emphasises how global improvements in premature mortality for select conditions have led to older populations with complex and potentially expensive diseases, yet also highlights global achievements in certain domains of disease and injury.

FUNDING

Bill & Melinda Gates Foundation.

Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND

The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 comparative risk assessment (CRA) is a comprehensive approach to risk factor quantification that offers a useful tool for synthesising evidence on risks and risk-outcome associations. With each annual GBD study, we update the GBD CRA to incorporate improved methods, new risks and risk-outcome pairs, and new data on risk exposure levels and risk-outcome associations.

METHODS

We used the CRA framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or groups of risks from 1990 to 2017. This study included 476 risk-outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk and exposure estimates from 46 749 randomised controlled trials, cohort studies, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. We explored the relationship between development and risk exposure by modelling the relationship between the Socio-demographic Index (SDI) and risk-weighted exposure prevalence and estimated expected levels of exposure and risk-attributable burden by SDI. Finally, we explored temporal changes in risk-attributable DALYs by decomposing those changes into six main component drivers of change as follows: (1) population growth; (2) changes in population age structures; (3) changes in exposure to environmental and occupational risks; (4) changes in exposure to behavioural risks; (5) changes in exposure to metabolic risks; and (6) changes due to all other factors, approximated as the risk-deleted death and DALY rates, where the risk-deleted rate is the rate that would be observed had we reduced the exposure levels to the TMREL for all risk factors included in GBD 2017.

FINDINGS

In 2017, 34·1 million (95% uncertainty interval [UI] 33·3-35·0) deaths and 1·21 billion (1·14-1·28) DALYs were attributable to GBD risk factors. Globally, 61·0% (59·6-62·4) of deaths and 48·3% (46·3-50·2) of DALYs were attributed to the GBD 2017 risk factors. When ranked by risk-attributable DALYs, high systolic blood pressure (SBP) was the leading risk factor, accounting for 10·4 million (9·39-11·5) deaths and 218 million (198-237) DALYs, followed by smoking (7·10 million [6·83-7·37] deaths and 182 million [173-193] DALYs), high fasting plasma glucose (6·53 million [5·23-8·23] deaths and 171 million [144-201] DALYs), high body-mass index (BMI; 4·72 million [2·99-6·70] deaths and 148 million [98·6-202] DALYs), and short gestation for birthweight (1·43 million [1·36-1·51] deaths and 139 million [131-147] DALYs). In total, risk-attributable DALYs declined by 4·9% (3·3-6·5) between 2007 and 2017. In the absence of demographic changes (ie, population growth and ageing), changes in risk exposure and risk-deleted DALYs would have led to a 23·5% decline in DALYs during that period. Conversely, in the absence of changes in risk exposure and risk-deleted DALYs, demographic changes would have led to an 18·6% increase in DALYs during that period. The ratios of observed risk exposure levels to exposure levels expected based on SDI (O/E ratios) increased globally for unsafe drinking water and household air pollution between 1990 and 2017. This result suggests that development is occurring more rapidly than are changes in the underlying risk structure in a population. Conversely, nearly universal declines in O/E ratios for smoking and alcohol use indicate that, for a given SDI, exposure to these risks is declining. In 2017, the leading Level 4 risk factor for age-standardised DALY rates was high SBP in four super-regions: central Europe, eastern Europe, and central Asia; north Africa and Middle East; south Asia; and southeast Asia, east Asia, and Oceania. The leading risk factor in the high-income super-region was smoking, in Latin America and Caribbean was high BMI, and in sub-Saharan Africa was unsafe sex. O/E ratios for unsafe sex in sub-Saharan Africa were notably high, and those for alcohol use in north Africa and the Middle East were notably low.

INTERPRETATION

By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning.

FUNDING

Bill & Melinda Gates Foundation.

Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND

The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017) includes a comprehensive assessment of incidence, prevalence, and years lived with disability (YLDs) for 354 causes in 195 countries and territories from 1990 to 2017. Previous GBD studies have shown how the decline of mortality rates from 1990 to 2016 has led to an increase in life expectancy, an ageing global population, and an expansion of the non-fatal burden of disease and injury. These studies have also shown how a substantial portion of the world's population experiences non-fatal health loss with considerable heterogeneity among different causes, locations, ages, and sexes. Ongoing objectives of the GBD study include increasing the level of estimation detail, improving analytical strategies, and increasing the amount of high-quality data.

METHODS

We estimated incidence and prevalence for 354 diseases and injuries and 3484 sequelae. We used an updated and extensive body of literature studies, survey data, surveillance data, inpatient admission records, outpatient visit records, and health insurance claims, and additionally used results from cause of death models to inform estimates using a total of 68 781 data sources. Newly available clinical data from India, Iran, Japan, Jordan, Nepal, China, Brazil, Norway, and Italy were incorporated, as well as updated claims data from the USA and new claims data from Taiwan (province of China) and Singapore. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between rates of incidence, prevalence, remission, and cause of death for each condition. YLDs were estimated as the product of a prevalence estimate and a disability weight for health states of each mutually exclusive sequela, adjusted for comorbidity. We updated the Socio-demographic Index (SDI), a summary development indicator of income per capita, years of schooling, and total fertility rate. Additionally, we calculated differences between male and female YLDs to identify divergent trends across sexes. GBD 2017 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting.

FINDINGS

Globally, for females, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and haemoglobinopathies and haemolytic anaemias in both 1990 and 2017. For males, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and tuberculosis including latent tuberculosis infection in both 1990 and 2017. In terms of YLDs, low back pain, headache disorders, and dietary iron deficiency were the leading Level 3 causes of YLD counts in 1990, whereas low back pain, headache disorders, and depressive disorders were the leading causes in 2017 for both sexes combined. All-cause age-standardised YLD rates decreased by 3·9% (95% uncertainty interval [UI] 3·1-4·6) from 1990 to 2017; however, the all-age YLD rate increased by 7·2% (6·0-8·4) while the total sum of global YLDs increased from 562 million (421-723) to 853 million (642-1100). The increases for males and females were similar, with increases in all-age YLD rates of 7·9% (6·6-9·2) for males and 6·5% (5·4-7·7) for females. We found significant differences between males and females in terms of age-standardised prevalence estimates for multiple causes. The causes with the greatest relative differences between sexes in 2017 included substance use disorders (3018 cases [95% UI 2782-3252] per 100 000 in males vs s1400 [1279-1524] per 100 000 in females), transport injuries (3322 [3082-3583] vs 2336 [2154-2535]), and self-harm and interpersonal violence (3265 [2943-3630] vs 5643 [5057-6302]).

INTERPRETATION

Global all-cause age-standardised YLD rates have improved only slightly over a period spanning nearly three decades. However, the magnitude of the non-fatal disease burden has expanded globally, with increasing numbers of people who have a wide spectrum of conditions. A subset of conditions has remained globally pervasive since 1990, whereas other conditions have displayed more dynamic trends, with different ages, sexes, and geographies across the globe experiencing varying burdens and trends of health loss. This study emphasises how global improvements in premature mortality for select conditions have led to older populations with complex and potentially expensive diseases, yet also highlights global achievements in certain domains of disease and injury.

FUNDING

Bill & Melinda Gates Foundation.

Non-invasive detection of coronary inflammation using computed tomography and prediction of residual cardiovascular risk (the CRISP CT study): a post-hoc analysis of prospective outcome data

BACKGROUND

Coronary artery inflammation inhibits adipogenesis in adjacent perivascular fat. A novel imaging biomarker-the perivascular fat attenuation index (FAI)-captures coronary inflammation by mapping spatial changes of perivascular fat attenuation on coronary computed tomography angiography (CTA). However, the ability of the perivascular FAI to predict clinical outcomes is unknown.

METHODS

In the Cardiovascular RISk Prediction using Computed Tomography (CRISP-CT) study, we did a post-hoc analysis of outcome data gathered prospectively from two independent cohorts of consecutive patients undergoing coronary CTA in Erlangen, Germany (derivation cohort) and Cleveland, OH, USA (validation cohort). Perivascular fat attenuation mapping was done around the three major coronary arteries-the proximal right coronary artery, the left anterior descending artery, and the left circumflex artery. We assessed the prognostic value of perivascular fat attenuation mapping for all-cause and cardiac mortality in Cox regression models, adjusted for age, sex, cardiovascular risk factors, tube voltage, modified Duke coronary artery disease index, and number of coronary CTA-derived high-risk plaque features.

FINDINGS

Between 2005 and 2009, 1872 participants in the derivation cohort underwent coronary CTA (median age 62 years [range 17-89]). Between 2008 and 2016, 2040 patients in the validation cohort had coronary CTA (median age 53 years [range 19-87]). Median follow-up was 72 months (range 51-109) in the derivation cohort and 54 months (range 4-105) in the validation cohort. In both cohorts, high perivascular FAI values around the proximal right coronary artery and left anterior descending artery (but not around the left circumflex artery) were predictive of all-cause and cardiac mortality and correlated strongly with each other. Therefore, the perivascular FAI measured around the right coronary artery was used as a representative biomarker of global coronary inflammation (for prediction of cardiac mortality, hazard ratio [HR] 2·15, 95% CI 1·33-3·48; p=0·0017 in the derivation cohort, and 2·06, 1·50-2·83; p<0·0001 in the validation cohort). The optimum cutoff for the perivascular FAI, above which there is a steep increase in cardiac mortality, was ascertained as -70·1 Hounsfield units (HU) or higher in the derivation cohort (HR 9·04, 95% CI 3·35-24·40; p<0·0001 for cardiac mortality; 2·55, 1·65-3·92; p<0·0001 for all-cause mortality). This cutoff was confirmed in the validation cohort (HR 5·62, 95% CI 2·90-10·88; p<0·0001 for cardiac mortality; 3·69, 2·26-6·02; p<0·0001 for all-cause mortality). Perivascular FAI improved risk discrimination in both cohorts, leading to significant reclassification for all-cause and cardiac mortality.

INTERPRETATION

The perivascular FAI enhances cardiac risk prediction and restratification over and above current state-of-the-art assessment in coronary CTA by providing a quantitative measure of coronary inflammation. High perivascular FAI values (cutoff ≥-70·1 HU) are an indicator of increased cardiac mortality and, therefore, could guide early targeted primary prevention and intensive secondary prevention in patients.

FUNDING

British Heart Foundation, and the National Institute of Health Research Oxford Biomedical Research Centre.

Exercise capacity in asymptomatic patients with significant primary mitral regurgitation: independent effect of global longitudinal left ventricular strain

Background

Despite preserved left ventricular ejection fraction (LVEF), patients with significant primary mitral regurgitation (MR) often have reduced exercise capacity. In asymptomatic patients with ≥3+ primary MR undergoing rest-stress echocardiography (RSE), we sought to evaluate the incremental impact of left ventricular global longitudinal strain (LV-GLS) on exercise capacity.

Methods

A total of 660 asymptomatic patients with ≥3+ primary MR, non-dilated LV and LVEF ≥60% (mean age, 57±14 years, 66% men, body mass index or BMI 25±4 kg/m²) who underwent RSE at our center between 2001 and 2013 were included. Standard RSE data were obtained. Average resting LV-GLS was measured using Velocity Vector Imaging.

Results

Mean mitral effective regurgitant orifice, resting right ventricular systolic pressure (RVSP) and LV-GLS were 0.45±0.2 cm², 31±12 mmHg and -21.7%±2%, respectively; 28% had flail mitral leaflet. Mean metabolic equivalents (METs) and post-stress RVSP were 9.9±3, and 46±15 mmHg; 28% achieved <100% age-gender predicted METs. No patient had ischemia or significant arrhythmias. On logistic regression, resting LV-GLS [odds ratio (OR), 1.40, 95% confidence interval (CI): 1.21-1.55, BMI (OR, 1.11, 95% CI: 1.06-1.17)] and resting RVSP 1.22 (1.02-1.49) were independent predictors of exercise capacity. Area under the curve for association between 100% age-gender predicted METs and various factors were as follows: (I) BMI (0.60, 95% CI: 0.55-0.65, P<0.001); (II) resting RVSP (0.57, 95% CI: 0.52-0.62, P=0.006) and LV-GLS (0.66, 95% CI: 0.61-0.70, P<0.001).

Conclusions

In asymptomatic patients with ≥3+ primary MR, non-dilated LV and preserved LVEF, LV-GLS is independently associated with exercise capacity, beyond known predictors.

Novel Echocardiographic Parameters in Patients With Aortic Stenosis and Preserved Left Ventricular Systolic Function Undergoing Surgical Aortic Valve Replacement

We sought to study the incremental prognostic impact of baseline valvuloarterial impedance (Zva) and left ventricular global longitudinal strain (LV-GLS) in patients with severe aortic stenosis and preserved left ventricular ejection fraction (LVEF) treated with surgical aortic valve replacement (AVR). We included 961 consecutive patients (68 ± 13 years; 63% men) with severe aortic stenosis (indexed aortic valve area <0.6 cm²) and LVEF >50% who underwent surgical AVR at our institution between January 2007 and December 2008. The analysis is based on derivation (n = 637) and validation (n = 324) subgroups. Society of Thoracic Surgeons (STS) score was calculated. Zva (systolic arterial pressure + mean aortic valve gradient)/left ventricular stroke volume index and LV-GLS (measured offline using Velocity Vector Imaging; Siemens Medical Solutions, Mountain View, California) were calculated. The primary outcome was death. Median Zva and LV-GLS were 4.5 mm Hg × ml^-1× m² and -14.5%, respectively. AVR was performed at a median of 34 days from initial evaluation (isolated AVR in 46%, bioprosthetic AVR in 93%). At 7.5 ± 3 years, 320 patients died (33%; 30 days/in-hospital death in 0.5%). In the derivation subgroup, on multivariate Cox survival analysis, higher STS score (hazard ratio [HR] 1.06), higher Zva (HR 1.13), and worse LV-GLS (HR 1.07) were independently associated with long-term survival (all p <0.01). When Zva and LV-GLS were sequentially added to STS score, the c-statistic improved from 0.63 [0.55 to 0.77] to 0.70 [0.60 to 0.81] and 0.78 [0.69 to 0.83], respectively, all p <0.001). Findings were confirmed in the validation subgroup. In conclusion, in patients with severe aortic stenosis and preserved LVEF treated with surgical AVR, baseline Zva and LV-GLS provide improved risk stratification with synergistic prognostic value.

Rate of Progression of Aortic Stenosis and its Impact on Outcomes in Patients With Radiation-Associated Cardiac Disease: A Matched Cohort Study

OBJECTIVES

The aim of this study was to study differences in progression of aortic stenosis (AS) in patients with mediastinal radiotherapy (XRT)-associated moderate AS versus a matched cohort during the same time frame, and to ascertain need for aortic valve replacement (AVR) and longer-term survival.

BACKGROUND

Rate of progression of XRT-associated moderate AS and its impact on outcomes is not well-described.

METHODS

We included 81 patients (age 61 ± 13 years; 57% female) with at least XRT-associated moderate AS (aortic valve area [AVA] 1.05 ± 0.3 cm²; mean gradient 24 ± 10 mm Hg) who had ≥2 transthoracic echocardiograms (TTEs) 1 year apart and matched them in a 1:2 fashion on the basis of age, sex, and AVA with those without prior XRT. Serial aortic valve gradients and AVA were recorded. AVR and longer-term all-cause mortality during follow-up were recorded.

RESULTS

A total of 100% of patients had 1, a total of 71% had 2, and 39% had 3 follow-up TTEs. Before AVR, mean AVG and AVA were not significantly different between XRT and comparison groups. At 3.6 ± 2.0 years from baseline TTE, 146 (60%) underwent AVR (16% transcatheter), with significantly more patients in the XRT group undergoing AVR (80% vs. 50%; p < 0.01), at a much shorter time (2.9 ± 1.6 years vs. 4.1 ± 2.4 years; p < 0.01). At 6.6 ± 4.0 years from the initial TTE, 49 (20%) patients died, with a significantly higher mortality in the XRT group (40% vs. 11%; p < 0.01), with prior XRT associated with increased longer-term mortality, whereas AVR was associated with improved longer-term survival.

CONCLUSIONS

In patients with moderate AS, those with prior XRT have a similar rate of progression of AS versus a comparison group. A higher proportion of patients in the XRT group were referred for AVR at a shorter time from baseline TTE. Despite that, the XRT patients had significantly higher longer-term mortality, and prior exposure to XRT was associated with significantly increased longer-term mortality.