Cohort comparison study of cardiac disease and atherosclerotic burden in type 2 diabetic adults using whole body cardiovascular magnetic resonance imaging

The early detection of atherosclerosis in type 1 diabetes: why, how and what to do about it

The major cause of morbidity and often premature mortality in people with type I diabetes (T1D) is cardiovascular disease owing to accelerated atherosclerosis. We review publications relating to the rationale behind, and clinical tests for, detecting and treating early atherosclerosis in people with T1D. Currently available tools for atherosclerosis assessment include risk equations using vascular risk factors, arterial intima-media thickness, the ankle-brachial index, coronary artery calcification and angiography, and for more advanced lesions, intravascular ultrasound and optical coherence tomography. Evolving research tools include risk equations incorporating novel clinical, biochemical and molecular tests; vascular MRI and molecular imaging. As yet there is little information available to quantify early atherosclerosis. With better means to control the vascular risk factors, such as hypertension, dyslipidaemia and glycaemic control, and emerging therapies to control novel risk factors, further epidemiologic and clinical trials are merited to facilitate the translation into clinical practice of robust means to detect, monitor and treat early atherosclerosis in those with T1D.

Prevalence and Distribution of Atherosclerosis in a Low- to Intermediate-Risk Population: Assessment with Whole-Body MR Angiography

Purpose To quantify the burden and distribution of asymptomatic atherosclerosis in a population with a low to intermediate risk of cardiovascular disease. Materials and Methods Between June 2008 and February 2013, 1528 participants with 10-year risk of cardiovascular disease less than 20% were prospectively enrolled. They underwent whole-body magnetic resonance (MR) angiography at 3.0 T by using a two-injection, four-station acquisition technique. Thirty-one arterial segments were scored according to maximum stenosis. Scores were summed and normalized for the number of assessable arterial segments to provide a standardized atheroma score (SAS). Multiple linear regression was performed to assess effects of risk factors on atheroma burden. Results A total of 1513 participants (577 [37.9%] men; median age, 53.5 years; range, 40-83 years) completed the study protocol. Among 46 903 potentially analyzable segments, 46 601 (99.4%) were interpretable. Among these, 2468 segments (5%) demonstrated stenoses, of which 1649 (3.5%) showed stenosis less than 50% and 484 (1.0%) showed stenosis greater than or equal to 50%. Vascular stenoses were distributed throughout the body with no localized distribution. Seven hundred forty-seven (49.4%) participants had at least one stenotic vessel, and 408 (27.0%) participants had multiple stenotic vessels. At multivariable linear regression, SAS correlated with age (B = 3.4; 95% confidence interval: 2.61, 4.20), heart rate (B = 1.23; 95% confidence interval: 0.51, 1.95), systolic blood pressure (B = 0.02; 95% confidence interval: 0.01, 0.03), smoking status (B = 0.79; 95% confidence interval: 0.44, 1.15), and socioeconomic status (B = -0.06; 95% confidence interval: -0.10, -0.02) (P < .01 for all). Conclusion Whole-body MR angiography identifies early vascular disease at a population level. Although disease prevalence is low on a per-vessel level, vascular disease is common on a per-participant level, even in this low- to intermediate-risk cohort. © RSNA, 2018 Online supplemental material is available for this article.

Development and Validation of a Path Length Calculation for Carotid-Femoral Pulse Wave Velocity Measurement: A TASCFORCE, SUMMIT, and Caerphilly Collaborative Venture

Supplemental Digital Content is available in the text.

Current distance measurement techniques for pulse wave velocity (PWV) calculation are susceptible to intercenter variability. The aim of this study was to derive and validate a formula for this distance measurement. Based on carotid femoral distance in 1183 whole-body magnetic resonance angiograms, a formula was derived for calculating distance. This was compared with distance measurements in 128 whole-body magnetic resonance angiograms from a second study. The effects of recalculation of PWV using the new formula on association with risk factors, disease discrimination, and prediction of major adverse cardiovascular events were examined within 1242 participants from the multicenter SUMMIT study (Surrogate Markers of Micro- and Macrovascular Hard End-Points for Innovative Diabetes Tools) and 825 participants from the Caerphilly Prospective Study. The distance formula yielded a mean error of 7.8 mm (limits of agreement =−41.1 to 56.7 mm; P<0.001) compared with the second whole-body magnetic resonance angiogram group. Compared with an external distance measurement, the distance formula did not change associations between PWV and age, blood pressure, or creatinine (P<0.01) but did remove significant associations between PWV and body mass index (BMI). After accounting for differences in age, sex, and mean arterial pressure, intercenter differences in PWV persisted using the external distance measurement (F=4.6; P=0.004), whereas there was a loss of between center difference using the distance formula (F=1.4; P=0.24). PWV odds ratios for cardiovascular mortality remained the same using both the external distance measurement (1.14; 95% confidence interval, 1.06–1.24; P=0.001) and the distance formula (1.17; 95% confidence interval, 1.08–1.28; P<0.001). A population-derived automatic distance calculation for PWV obtained from routinely collected clinical information is accurate and removes intercenter measurement variability without impacting the diagnostic utility of carotid–femoral PWV.

Epicardial adipose tissue is related to arterial stiffness and inflammation in patients with cardiovascular disease and type 2 diabetes

Background

Epicardial adipose tissue (EAT) is an emerging cardio-metabolic risk factor and has been shown to correlate with adverse cardiovascular (CV) outcome; however the underlying pathophysiology of this link is not well understood. The aim of this study was to evaluate the relationship between EAT and a comprehensive panel of cardiovascular risk biomarkers and pulse wave velocity (PWV) and indexed left ventricular mass (LVMI) in a cohort of patients with cardiovascular disease (CVD) and diabetes compared to controls.

Methods

One hundred forty-five participants (mean age 63.9 ± 8.1 years; 61% male) were evaluated. All patients underwent cardiovascular magnetic resonance (CMR) examination and PWV. EAT measurements from CMR were performed on the 4-chamber view. Blood samples were taken and a range of CV biomarkers was evaluated.

Results

EAT measurements were significantly higher in the groups with CVD, with or without T2DM compared to patients without CVD or T2DM (group 1 EAT 15.9 ± 5.5 cm² vs. group 4 EAT 11.8 ± 4.1 cm², p = 0.001; group 3 EAT 15.1 ± 4.3 cm² vs. group 4 EAT 11.8 ± 4.1 cm², p = 0.024). EAT was independently associated with IL-6 (beta 0.2, p = 0.019). When added to clinical variables, both EAT (beta 0.16, p = 0.035) and IL-6 (beta 0.26, p = 0.003) were independently associated with PWV. EAT was significantly associated with LVMI in a univariable analysis but not when added to significant clinical variables.

Conclusions

In patients with cardio-metabolic disease, EAT was independently associated with PWV. EAT may be associated with CVD risk due to an increase in systemic vascular inflammation. Whether targeting EAT may reduce inflammation and/or cardiovascular risk should be evaluated in prospective studies.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0770-z) contains supplementary material, which is available to authorized users.

Systemic arteriosclerosis is associated with left ventricular remodeling but not atherosclerosis: a TASCFORCE study

BACKGROUND

Arteriosclerosis (arterial stiffening) is associated with future cardiovascular events, with this effect postulated to be due to its effect on cardiac afterload, atherosclerosis (plaque formation) progression or both, but with limited evidence examining these early in disease formation. The aim of the current study is to examine the association between arteriosclerosis, atherosclerosis and ventricular remodelling in a population at low-intermediate cardiovascular risk.

METHODS

One thousand six hundred fifty-one subjects free of clinical cardiovascular disease and with a < 20% 10 year cardiovascular risk score underwent a cardiovascular magnetic resonance (CMR) study and whole body CMR angiogram. Arteriosclerosis was measured using total arterial compliance (TAC) - calculated as the indexed stroke volume divided by the pulse pressure. Atherosclerosis was quantified using a standardised atheroma score (SAS) which was calculated by scoring 30 arterial segments within the body based on the degree of stenosis, summating these scores and normalising it to the number of assessable segments. Left ventricular remodelling was measured using left ventricular mass to volume ratio (LVMVR).

RESULTS

One thousand five hundred fifteen (38% male, 53.8 ± 8.2 years old) completed the study. On univariate analysis TAC was associated with SAS but this was lost after accounting for cardiovascular risk factors in both males (B = - 0.001 (- 0.004-0.002),p = 0.62) and females (B = 0.000(95%CI -0.002--0.002),p = 0.78). In contrast compliance correlated with LVMVR after accounting for cardiovascular risk factors (B = - 0.12(95%CI -0.16--0.091),p < 0.001 in males; B = - 0.12(95%CI -0.15--0.086),p < 0.001 in females).

CONCLUSION

Systemic arteriosclerosis is associated with left ventricular remodelling but not atherosclerosis. Future efforts in cardiovascular risk prevention should thus seek to address both arteriosclerosis and atherosclerosis individually.

Prevalence of unrecognized myocardial infarction in a low-intermediate risk asymptomatic cohort and its relation to systemic atherosclerosis

Aims

Unrecognized myocardial infarctions (UMIs) have been described in 19–30% of the general population using late gadolinium enhancement (LGE) on cardiac magnetic resonance. However, these studies have focused on an unselected cohort including those with known cardiovascular disease (CVD). The aim of the current study was to ascertain the prevalence of UMIs in a non-high-risk population using magnetic resonance imaging (MRI).

Methods and results

A total of 5000 volunteers aged >40 years with no history of CVD and a 10-year risk of CVD of <20%, as assessed by the ATP-III risk score, were recruited to the Tayside Screening for Cardiac Events study. Those with a B-type natriuretic peptide (BNP) level greater than their gender-specific median were invited for a whole-body MR angiogram and cardiac MR including LGE assessment. LGE was classed as absent, UMI, or non-specific. A total of 1529 volunteers completed the imaging study; of these, 53 (3.6%) were excluded because of either missing data or inadequate LGE image quality. Ten of the remaining 1476 (0.67%) displayed LGE. Of these, three (0.2%) were consistent with UMI, whereas seven were non-specific occurring in the mid-myocardium (n = 4), epicardium (n = 1), or right ventricular insertion points (n = 2). Those with UMI had a significantly higher BNP [median 116 (range 31–133) vs. 22.6 (5–175) pg/mL, P = 0.015], lower ejection fraction [54.6 (36–62) vs. 68.9 (38–89)%, P = 0.007], and larger end-systolic volume [36.3 (27–61) vs. 21.7 (5–65) mL/m², P = 0.014]. Those with non-specific LGE had lower diastolic blood pressure [68 (54–70) vs. 72 (46–98) mmHg, P = 0.013] but no differences in their cardiac function.

Conclusion

Despite previous reports describing high prevalence of UMI in older populations, in a predominantly middle-aged cohort, those who are of intermediate or low cardiovascular risk have a very low risk of having an unrecognized myocardial infarct.

Effects of inaccuracies in arterial path length measurement on differences in MRI and tonometry measured pulse wave velocity

BACKGROUND

Carotid-femoral pulse wave velocity (cf-PWV) and aortic PWV measured using MRI (MRI-PWV) show good correlation, but with a significant and consistent bias across studies. The aim of the current study was to evaluate whether the differences between cf.-PWV and MRI-PWV can be accounted for by inaccuracies of currently used distance measurements.

METHODS

One hundred fourteen study participants were recruited into one of 4 groups: Type 2 diabetes melltus (T2DM) with cardiovascular disease (CVD) (n = 23), T2DM without CVD (n = 41), CVD without T2DM (n = 25) and a control group (n = 25). All participants underwent cf.-PWV, cardiac MRI and whole body MR angiography(WB-MRA). 90 study participants also underwent aortic PWV using MRI. cf.-PWVEXT was performed using a SphygmoCor device (Atcor Medical, West Ryde, Australia). The true intra-arterial pathlength was measured using the WB-MRA and then used to recalculate the cf.-PWVEXT to give a cf.-PWVMRA.

RESULTS

Distance measurements were significantly lower on WB-MRA than on external tape measure (mean diff = -85.4 ± 54.0 mm,p < 0.001). MRI-PWV was significantly lower than cf.-PWVEXT (MRI-PWV = 8.1 ± 2.9 vs. cf.-PWVEXT = 10.9 ± 2.7 ms-1,p < 0.001). When cf.-PWV was recalculated using the inter-arterial distance from WB-MRA, this difference was significantly reduced but not lost (MRI-PWV = 8.1 ± 2.9 ms-1 vs. cf.-PWVMRA 9.1 ± 2.1 ms-1, mean diff = -0.96 ± 2.52 ms-1,p = 0.001). Recalculation of the PWV increased correlation with age and pulse pressure.

CONCLUSION

Differences in cf.-PWV and MRI PWV can be predominantly but not entirely explained by inaccuracies introduced by the use of simple surface measurements to represent the convoluted arterial path between the carotid and femoral arteries.

Whole-body cardiovascular MRI for the comparison of atherosclerotic burden and cardiac remodelling in healthy South Asian and European adults

OBJECTIVE

To determine the feasibility of using whole-body cardiovascular MRI (WB-CVMR) to compare South Asians (SAs)-a population known to have a higher risk of cardiovascular disease (CVD) but paradoxically lower prevalence of peripheral arterial disease-and Western Europeans (WEs).

METHODS

19 SAs and 38 age-, gender- and body mass index-matched WEs were recruited. All were aged 40 years and over, free from CVD and with a 10-year risk of CVD <20% as assessed by the adult treatment panel (ATP) III risk score. WB-CVMR was performed, comprising a whole-body angiogram (WBA) and cardiac MR (CMR), on a 3-T MRI scanner (Magnetom(®) Trio; Siemens, Erlangen, Germany) following dual-phase injection of gadolinium-based contrast agent. A standardized atheroma score (SAS) was calculated from the WBA while indexed left ventricular mass and volumes were calculated from the CMR.

RESULTS

SAs exhibited a significantly lower iliofemoral atheroma burden (regional SAS 0.0 ± 0.0 vs 1.9 ± 6.9, p = 0.048) and a trend towards lower overall atheroma burden (whole-body SAS 0.7 ± 0.8 vs 1.8 ± 2.3, p = 0.1). They had significantly lower indexed left ventricular mass (46.9 ± 11.8 vs 56.9 ± 13.4 ml m(-2), p = 0.008), end diastolic volume (63.9 ± 10.4 vs 75.2 ± 11.4 ml m(-2), p=0.001), end systolic volume (20.5 ± 6.1 vs 24.6 ± 6.8 ml m(-2), p = 0.03) and stroke volume (43.4 ± 6.6 vs 50.6 ± 7.9 ml m(-2), p = 0.001), but with no significant difference in ejection fraction, mass-volume ratio or global functioning index. These differences persisted after accounting for CVD risk factors.

CONCLUSION

WB-CVMR can quantify cardiac and atheroma burden and can detect differences in these metrics between ethnic groups that, if validated, may suggest that the paradoxical high risk of CVD compared with PVD risk may be due to an adverse cardiac haemodynamic status incurred by the smaller heart rather than atherosclerosis.

ADVANCES IN KNOWLEDGE

WB-CVMR can be used to stratify and compare disease between ethnicities.

Statin use and cardiovascular risk factors in diabetic patients developing a first myocardial infarction

BACKGROUND

The risk for a first myocardial infarction (MI) in people with diabetes has been shown to be as high as the risk for a new MI in non-diabetic patients with a prior MI. Consequently, risk-reducing statin therapy is recommended for nearly all patients with diabetes 40 years of age or older, regardless of cholesterol level. The purpose of this study was to assess the recommended and real-life use of statins for primary prevention of atherosclerotic cardiovascular disease (ASCVD) in diabetic patients who develop ASCVD.

METHODS

In a cross-sectional multicenter study of consecutive patients without previous ASCVD hospitalized with a first MI in 2010-2012, we obtained information on diabetic status, statin use, and cardiovascular risk factors prior to MI.

RESULTS

The study population consisted of 1622 patients with first MI (63 % men), 228 of whom had known diabetes before MI. All but three of the diabetic patients were ≥40 years of age. Diabetic patients were older (70 vs 68, p = 0.006), were more often women (43 vs 36 %, p = 0.05) and had a higher prevalence of statin use (47 vs 11 %, p < 0.001) compared with non-diabetic patients. Despite a high risk factor burden, the majority (53 %) of patients with known diabetes was not treated with statins before MI, and there was no relationship between the number of high-risk markers and statin use. Nearly all diabetic patients not treated with statins before first MI had at least one marker of very high cardiovascular risk, including hypertension (71 %), current smoking (37 %), and nephropathy (33 %).

CONCLUSIONS

Primary prevention with statins had been initiated in less than half of diabetic patients destined for a first MI, despite the presence of one or more markers of very high cardiovascular risk in nearly all. These results highlight an urgent need for optimizing statin therapy and global risk factor control in diabetic patients.

Diabetes is an independent predictor of right ventricular dysfunction post ST-elevation myocardial infarction

BACKGROUND

Diabetes mellitus (DM) is estimated to become the 7th leading cause of death by 2030. Right ventricular dysfunction (RVD) complicating ST elevation myocardial infarction (STEMI) is independently associated with a higher mortality; however the relationship between DM and RVD is currently unknown. The purpose of this study was to determine whether DM is an independent predictor for the presence of right ventricular dysfunction (RVD) post STEMI.

METHODS

106 patients post primary PCI for STEMI were enrolled in the study. Cardiac MRI was performed within 48-72 h after admission in order to assess ventricular function. Statistical analysis consisted initially of descriptive statistics including Chi square, Fisher's exact, or the Wilcoxon rank sum as appropriate. Subsequently, logistic regression analysis was performed to determine independent predictors of RVD.

RESULTS

The median age in the study was 58 years (IQR 53, 67). 30 % of the patients had diabetes. Of 99 patients for which RV data was available, 40 had RVD and 59 did not. Patients with DM were significantly more likely to have RVD when compared to those without diabetes (45 vs 22 %, p = 0.03). There was no significant difference in age, hypertension, smoking status, dyslipidemia, serum creatinine or peak CK levels between the two groups. After adjusting for other factors, presence of DM remained an independent predictor for the presence of RV dysfunction (OR 2.78, 95 % CI 1.12, 6.87, p = 0.03). Amongst diabetic patients, those with HbA1C ≥ 7 % had greater odds of having RVD vs those with HbA1C < 7 % (OR 5.58 (1.20, 25.78), p = 0.02).

CONCLUSIONS

The presence of DM conferred an approximately threefold greater odds of being associated with RVD post STEMI. No other major cardiovascular risk factors were independently associated with the presence of RVD.

Follow-up of atheroma burden with sequential whole body contrast enhanced MR angiography: a feasibility study

Assess the feasibility of whole body magnetic resonance angiography (WB-MRA) for monitoring global atheroma burden in a population with peripheral arterial disease (PAD). 50 consecutive patients with symptomatic PAD referred for clinically indicated MRA were recruited. Whole body MRA (WB-MRA) was performed at baseline, 6 months and 3 years. The vasculature was split into 31 anatomical arterial segments. Each segment was scored according to degree of luminal narrowing: 0 = normal, 1 = <50 %, 2 = 50–70 %, 3 = 71–99 %, 4 = vessel occlusion. The score from all assessable segments was summed, and then normalised to the number of assessable vessels. This normalised score was divided by four (the maximum vessel score) and multiplied by 100 to give a final standardised atheroma score (SAS) with a score of 0–100. Progression was assessed with repeat measure ANOVA. 36 patients were scanned at 0 and 6 months, with 26 patients scanned at the 3 years follow up. Only those who completed all three visits were included in the final analysis. Baseline atherosclerotic burden was high with a mean SAS of 15.7 ± 10.3. No significant progression was present at 6 months (mean SAS 16.4 ± 10.5, p = 0.67), however there was significant disease progression at 3 years (mean SAS 17.7 ± 11.5, p = 0.01). Those with atheroma progression at follow-up were less likely to be on statin therapy (79 vs 100 %, p = 0.04), and had significantly higher baseline SAS (17.6 ± 11.2 vs 10.7 ± 5.1, p = 0.043). Follow up of atheroma burden is possible with WB-MRA, which can successfully quantify and monitor atherosclerosis progression at 3 years follow-up.