Indigenizing Cardiac Rehabilitation: The Role for Cultural Adaptation.

Cardiac rehabilitation (CR) is an integral component of cardiovascular care, which reduces morbidity and mortality, and improves quality of life. Largely as a result of Canada's colonial history, Indigenous communities face higher rates of cardiovascular morbidity and mortality. Indigenous Peoples in Canada have a unique cultural, historical, and geographic context that limits access to high-quality cardiovascular care, including CR, which has traditionally been delivered in an urban, hospital-based setting. Culturally adapted, holistic exercise and diet programs and CR programs have been successful in Canada, Australia, and New Zealand, demonstrating acceptability to the community, safety, and improvements in cardiovascular risk factors. Key components of a successful culturally adapted CR program include program leadership and development by Indigenous community members and key partners, cultural sensitivity training for health care providers and financial and geographic accessibility. Encouragement of traditional practices, including healthy traditional dietary practices, and recognizing land-based activities as exercise have also proved important in the successful delivery of CR in Indigenous communities. This review summarizes the current evidence for culturally adapted CR programming for Indigenous patients, including strategies to engage communities in education on cardiovascular risk-factor optimization and to promote guideline-based exercise and diet through an Indigenous lens.

The Morphology of Coronary Artery Disease in South Asians vs White Caucasians and Its Implications.

South Asians (SAs) experience a higher prevalence and earlier onset of coronary artery disease and have worse outcomes compared with White Caucasians (WCs) following invasive revascularisation procedures, a mainstay of coronary artery disease (CAD) management. We sought to review the differences in the CAD pattern and risk factors between SA and WC patients and to discuss their potential impact on the development of coronary disease, acute coronary syndrome, and revascularisation outcomes. SAs have a more diffuse pattern with multivessel involvement compared with WCs. However, less is known about other morphologic characteristics, such as calcification of atherosclerotic plaque and coronary diameter in SA populations. Despite a similar coronary calcification burden, higher noncalcified plaque composition, elevated thrombosis, and inflammatory markers likely contribute to the disease pattern. Although the current evidence on the role of coronary vessel size remains inconsistent, smaller diameters in SAs could play a potential role in the higher disease prevalence. This is especially important given the impact of coronary artery diameter on revascularisation outcomes. In conclusion, SAs have a unique CAD risk profile composed of traditional and novel risk factors. Our findings highlight the need for additional awareness of health professionals of this specific risk profile and potential therapeutic targets, as well as the need for further research in this vulnerable population.

Symptom subtypes and risk of incident cardiovascular and cerebrovascular disease in a clinic-based obstructive sleep apnea cohort.

STUDY OBJECTIVES: Patients with obstructive sleep apnea (OSA) are at increased risk of cardiovascular and cerebrovascular disease, but predicting those at greatest risk is challenging. Using latent class analysis, patients with OSA can be placed into discrete symptom subtypes. The aim of this study was to determine whether symptom subtypes are associated with future cerebrovascular disease in patients with OSA in a clinic-based cohort. METHODS: Patients with suspected OSA referred for a polysomnogram at an academic sleep center completed a comprehensive symptom survey. Patients with OSA (apnea-hypopnea index ≥ 5 events/h) were then placed into symptom subtypes based on responses to survey questions using latent class analysis. Cardiovascular events (stroke, myocardial infarction, unstable angina, bypass grafting, percutaneous coronary intervention, cardiac resynchronization therapy, defibrillation) occurring within 8 years of polysomnogram were identified by linkage to provincial health databases. RESULTS: 1,607 patients were studied, of whom 1,292 had OSA. One hundred forty first events occurred within 8 years of polysomnogram. Patients in the excessively sleepy with disturbed sleep subtype had a significantly increased rate of events compared to the minimally symptomatic subtype (hazard ratio = 2.25, 95% confidence interval: 1.02-4.94; P = .04). Two symptoms (restless legs and dozing off or sleeping while talking to someone) were significantly associated with future risk of cerebrovascular disease (hazard ratio = 1.68, 1.12-2.49 and 4.23, 1.61-11.16, respectively). CONCLUSIONS: Patients with OSA in the clinic who are in the excessively sleepy with disturbed sleep subtype are significantly more likely to have a future cardiovascular event. This underscores the importance of understanding clinical heterogeneity and incorporating symptom subtype definitions into routine clinical care. CITATION: Allen AJH, Jen R, Mazzotti DR, et al. Symptom subtypes and risk of incident cardiovascular and cerebrovascular disease in a clinic-based obstructive sleep apnea cohort. J Clin Sleep Med. 2022;18(9):2093-2102.

Myocardial Infarction Injury in Patients with Chronic Lung Disease Entering Pulmonary Rehabilitation: Frequency and Association with Heart Rate Parameters.

BACKGROUND: Myocardial infarction (MI) remains under-recognized in chronic lung disease (CLD) patients. Rehabilitation health professionals need accessible clinical measurements to identify the presence of prior MI in order to determine appropriate training prescription. OBJECTIVES: To estimate prior MI in CLD patients entering a pulmonary rehabilitation program, as well as its association with heart rate parameters such as resting heart rate and chronotropic response index. DESIGN: Retrospective cohort design. SETTING: Pulmonary rehabilitation outpatient clinic in a tertiary care university-affiliated hospital. PATIENTS: Eighty-five CLD patients were studied. METHODS: Electrocardiograms at rest and peak cardiopulmonary exercise testing, performed before pulmonary rehabilitation, were analyzed. Electrocardiographic evidence of prior MI, quantified by the Cardiac Infarction Injury Score (CIIS), was contrasted with reported myocardial events and then correlated with resting heart rate and chronotropic response index parameters. MAIN OUTCOME MEASUREMENTS: CIIS, resting heart rate, and chronotropic response index. RESULTS: Sixteen CLD patients (19%) demonstrated electrocardiographic evidence of prior MI, but less than half (8%) had a reported MI history (P < .05). The Cohen's kappa test revealed poor level of agreement between CIIS and medical records (kappa = 0.165), indicating that prior MI diagnosis was under-reported in the medical records. Simple and multiple regression analyses showed that resting heart rate but not chronotropic response index was positively associated with CIIS in our population (R2 = 0.29, P < .001). CLD patients with a resting heart rate higher than 80 beats/min had approximately 5 times higher odds of having prior MI, as evidenced by a CIIS ≥ 20. CONCLUSIONS: CLD patients entering pulmonary rehabilitation are at risk of unreported prior MI. Elevated resting heart rate appears to be an indicator of prior MI in CLD patients; therefore, careful adjustment of training intensity is recommended under these circumstances. LEVEL OF EVIDENCE: III.

Surgical Versus Percutaneous Coronary Revascularization in Patients With Diabetes and Acute Coronary Syndromes.

BACKGROUND: Randomized trial data support the superiority of coronary artery bypass grafting (CABG) surgery over percutaneous coronary intervention (PCI) in diabetic patients with multivessel coronary artery disease (MV-CAD). However, whether this benefit is seen in a real-world population among subjects with stable ischemic heart disease (SIHD) and acute coronary syndromes (ACS) is unknown. OBJECTIVES: The main objective of this study was to assess the generalizability of the FREEDOM (Future REvascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multi-vessel Disease) trial in real-world practice among patients with diabetes mellitus and MV-CAD in residents of British Columbia, Canada. Additionally, the study evaluated the impact of mode of revascularization (CABG vs. PCI with drug-eluting stents) in diabetic patients with ACS and MV-CAD. METHODS: In a large population-based database from British Columbia, this study evaluated major cardiovascular outcomes in all diabetic patients who underwent coronary revascularization between 2007 and 2014 (n = 4,661, 2,947 patients with ACS). The primary endpoint (major adverse cardiac or cerebrovascular events [MACCE]) was a composite of all-cause death, nonfatal myocardial infarction, and nonfatal stroke. The risk of MACCE with CABG or PCI was compared using multivariable adjustment and a propensity score model. RESULTS: At 30-days post-revascularization, for ACS patients the odds ratio for MACCE favored CABG 0.49 (95% confidence interval [CI]: 0.34 to 0.71), whereas among SIHD patients MACCE was not affected by revascularization strategy (odds ratio: 1.46; 95% CI: 0.71 to 3.01; pinteraction <0.01). With a median follow-up of 3.3 years, the late (31-day to 5-year) benefit of CABG over PCI no longer varied by acuity of presentation, with a hazard ratio for MACCE in ACS patients of 0.67 (95% CI: 0.55 to 0.81) and the hazard ratio for SIHD patients of 0.55 (95% CI: 0.40 to 0.74; pinteraction = 0.28). CONCLUSIONS: In diabetic patients with MV-CAD, CABG was associated with a lower rate of long-term MACCE relative to PCI for both ACS and SIHD. A well-powered randomized trial of CABG versus PCI in the ACS population is warranted because these patients have been largely excluded from prior trials.

Cardiovascular consequences of obstructive sleep apnea.

PURPOSE OF REVIEW: There is an increased awareness of obstructive sleep apnea (OSA) and its potential impact on cardiovascular diseases (CVDs). The number of patients diagnosed with OSA is likely to increase as the obesity epidemic continues to grow. We review recent publications that have examined the links between OSA and CVD. RECENT FINDINGS: The cardiovascular consequences of OSA include hypertension, strokes, atrial fibrillation, and heart failure. It is likely that these are related to OSA-induced changes in endothelial dysfunction, oxidative stress, and systemic inflammation. The mainstay of treatment of OSA remains positive airway pressure devices (PAP), but issues of adherence continue to plague effective management. Oral appliances may also be a suitable alternative and may have a similar effect on blood pressure as PAP. To date, randomized trials have verified a significant (though relatively modest) impact of PAP on blood pressure, and some have shown an improvement in glucose control in diabetic individuals. However, it is unclear whether PAP prevents cardiovascular events in patients with OSA, although patients well managed and adherent with PAP seem to do better than those who are nonadherent. SUMMARY: The mortality and morbidity associated with OSA are reduced in patients well managed with PAP. However, we await the results of large randomized clinical trials to definitely determine whether PAP reduces the rate of cardiovascular events. Current efforts aimed at identifying biomarkers in OSA may offer a strategy for personalized treatment plans of OSA patients.

Prevalence and Associated Clinical Characteristics of Exercise-Induced ST-Segment Elevation in Lead aVR.

BACKGROUND: Exercise-induced ST-segment elevation (STE) in lead aVR may be an important indicator of prognostically important coronary artery disease (CAD). However, the prevalence and associated clinical features of exercise-induced STE in lead aVR among consecutive patients referred for exercise stress electrocardiography (ExECG) is unknown. METHODS: All consecutive patients receiving a Bruce protocol ExECG for the diagnosis of CAD at a tertiary care academic center were included over a two-year period. Clinical characteristics, including results of coronary angiography, were compared between patients with and without exercise-induced STE in lead aVR. RESULTS: Among 2227 patients undergoing ExECG, exercise-induced STE ≥1.0mm in lead aVR occurred in 3.4% of patients. Patients with STE in lead aVR had significantly lower Duke Treadmill Scores (DTS) (-0.5 vs. 7.0, p<0.01) and a higher frequency of positive test results (60.2% vs. 7.3%, p<0.01). Furthermore, patients with STE in lead aVR were more likely to undergo subsequent cardiac catheterization than those without STE in lead aVR (p<0.01, odds ratio = 4.2). CONCLUSIONS: Among patients referred for ExECG for suspected CAD, exercise-induced STE in lead aVR was associated with a higher risk DTS, an increased likelihood of a positive ExECG, and referral for subsequent coronary angiography. These results suggest that exercise-induced STE in lead aVR may represent a useful ECG feature among patients undergoing ExECG in the risk stratification of patients.

The First Dedicated Cardiac Rehabilitation Program for Patients With Spontaneous Coronary Artery Dissection: Description and Initial Results.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is an important cause of myocardial infarction in women, but the role of rehabilitation after SCAD is unclear. METHODS: We designed a dedicated SCAD cardiac rehabilitation (SCAD-CR) program for our SCAD survivors at Vancouver General Hospital. This program encompasses a multidisciplinary approach including exercise rehabilitation, psychosocial counselling, dietary and cardiovascular disease education, and peer group support. Exercise and educational classes were scheduled weekly with a targeted participation of 6 months. Psychosocial counselling, mindful living sessions, social worker and psychiatry evaluations, and peer-group support were offered. RESULTS: We report our first consecutive cohort of 70 SCAD women who joined SCAD-CR from November 2011 to April 2015. The average age was 52.3 ± 8.4 years. Mean participation duration was 12.4 ± 10.5 weeks; 28 completed 6 months, 48 completed ≥ 1 month. At entry, 44 (62.9%) had recurrent chest pains and average metabolic equivalents on exercise treadmill test was 10.1 ± 3.3. At program exit, the proportion with recurrent chest pains was lower (37.1%) and average metabolic equivalents was higher 11.5 ± 3.5 (both P < 0.001). There was a significant improvement in the STOP-D depression questionnaire, with mean scores of 13.0 ± 1.4 before and 8.0 ± 1.7 after the SCAD-CR (P = 0.046). Twenty (28.6%) social worker referrals and 19 (27.1%) psychiatry referrals were made. Mean follow-up was 3.8 ± 2.9 years from the presenting SCAD event, and the major cardiac adverse event rate was 4.3%, lower than our non-SCAD-CR cohort (n = 145; 26.2%; P < 0.001). CONCLUSIONS: This is the first dedicated SCAD-CR program to address the unique exercise and psychosocial needs of SCAD survivors. Our program appears safe and beneficial in improving chest pain, exercise capacity, psychosocial well-being and cardiovascular events.

Sex-based prognostic implications of nonobstructive coronary artery disease: results from the international multicenter CONFIRM study.

PURPOSE: To determine the clinical outcomes of women and men with nonobstructive coronary artery disease ( CAD coronary artery disease ) with coronary computed tomographic (CT) angiography data in patients who were similar in terms of CAD coronary artery disease risk factors, angina typicality, and CAD coronary artery disease extent and distribution. MATERIALS AND METHODS: Institutional review board approval was obtained for all participating sites, with either informed consent or waiver of informed consent. In a prospective international multicenter cohort study of 27 125 patients undergoing coronary CT angiography at 12 centers, 18 158 patients with no CAD coronary artery disease or nonobstructive (<50% stenosis) CAD coronary artery disease were examined. Men and women were propensity matched for age, CAD coronary artery disease risk factors, angina typicality, and CAD coronary artery disease extent and distribution, which resulted in a final cohort of 11 462 subjects. Nonobstructive CAD coronary artery disease presence and extent were related to incident major adverse cardiovascular events ( MACE major adverse cardiovascular events ), which were inclusive of death and myocardial infarction and were estimated by using multivariable Cox proportional hazards models. RESULTS: At a mean follow-up ± standard deviation of 2.3 years ± 1.1, MACE major adverse cardiovascular events occurred in 164 patients (0.6% annual event rate). After matching, women and men experienced identical annualized rates of myocardial infarction (0.2% vs 0.2%, P = .72), death (0.5% vs 0.5%, P = .98), and MACE major adverse cardiovascular events (0.6% vs 0.6%, P = .94). In multivariable analysis, nonobstructive CAD coronary artery disease was associated with similarly increased MACE major adverse cardiovascular events for both women (hazard ratio: 1.96 [95% confidence interval { CI confidence interval }: 1.17, 3.28], P = .01) and men (hazard ratio: 1.77 [95% CI confidence interval : 1.07, 2.93], P = .03). CONCLUSION: When matched for age, CAD coronary artery disease risk factors, angina typicality, and nonobstructive CAD coronary artery disease extent, women and men experience comparable rates of incident mortality and myocardial infarction.

Assessment of sex differences in plaque morphology by coronary computed tomography angiography--are men and women the same?

PURPOSE: The objective of this study was to assess whether sex differences exist in plaque burden and plaque subtype as assessed by coronary computed tomography angiography (CCTA). METHODS: The study cohort included 937 consecutive patients who underwent CCTA between 2008 and 2010. Stenosis was quantified using the Society of Cardiovascular Computed Tomography stenosis grading scale and a total stenosis score (TSS) was generated. Plaque morphology (PM) was reported as predominantly calcified (CP), noncalcified (NCP), or mixed (MP) plaque, and CP, NCP, and MP percentages were calculated. RESULTS: On multivariate analysis, men were significantly more likely to have plaque (65.9% of men vs. 44.6% of women, p<0.001), at least one segment with ≥50% stenosis (22.7% of men vs. 10.3% of women, p<0.001) and higher TSS (mean score=2.81 for men vs. 1.58 for women, p<0.001). Sex was the strongest predictor in all models (odds ratio [OR]=2.55, 95% confidence interval [CI] 1.78-3.67, p<0.001 for any plaque; OR=2.48, 95% CI 1.48-4.16, p<0.01 for segments with ≥50% stenosis; ß=1.46, 95% CI 0.69-2.22, p<0.001 for TSS). Among patients with coronary plaque present, no significant sex differences in PM were found. CONCLUSIONS: Sex was the strongest risk factor for the presence and extent of plaque. Significant sex differences in PM did not exist.

Early atherosclerosis detection in asymptomatic patients: a comparison of carotid ultrasound, coronary artery calcium score, and coronary computed tomography angiography.

BACKGROUND: Detailed multimodality assessment of subclinical atherosclerosis in asymptomatic subjects referred for risk stratification has not been performed. We analyzed the detection of early atherosclerosis using 3 imaging modalities: coronary artery calcium (CAC) scoring, carotid ultrasound (US), and coronary computed tomography angiography (CCTA). METHODS: Asymptomatic subjects free of known vascular disease scheduled to undergo a carotid US for risk stratification were invited to undergo CCTA/CAC. Subjects taking lipid-lowering medication were excluded. All images were assessed by experienced core laboratory personnel. Carotid intima media thickness ≥ 75th percentile for age and sex, CAC > 0, and detection of either carotid or coronary artery plaque were indicators of atherosclerosis. RESULTS: Fifty patients were included with a median age of 53 years. Atherosclerosis was observed in 28%, 78%, and 90% of subjects using CAC, CCTA, and carotid US, respectively. All subjects showed atherosclerosis on at least 1 modality. In 36 patients with a CAC score = 0, 69% and 86% had atherosclerosis on CCTA and carotid US, respectively. CONCLUSIONS: In this detailed analysis, all subjects identified to warrant further risk stratification had subclinical atherosclerosis on at least 1 imaging modality. Concordance between modalities was highly variable, dependent on the specific definition of atherosclerosis used. Carotid US and CCTA detection of plaque were significantly more sensitive than CAC > 0 in this middle-aged population. Considering the prevalence of subclinical disease on carotid US and CCTA, the threshold at which to treat warrants further research.

Cardiovascular risk among stable individuals suspected of having coronary artery disease with no modifiable risk factors: results from an international multicenter study of 5262 patients.

PURPOSE: To assess the prevalence, extent, severity, and risk of coronary artery disease (CAD) in patients suspected of having CAD but with no medically modifiable risk factors. MATERIALS AND METHODS: Institutional review board approval or waiver of consent was obtained at each center. This study was HIPAA compliant. From an international multicenter cohort study of 27 125 subjects undergoing coronary computed tomographic (CT) angiography from 12 centers, 5262 patients without known CAD and without modifiable risk factors were identified. CAD severity was defined as none (0%), mild (1%-49%), or obstructive (≥ 50%) on a per-patient, per-vessel, and per-segment basis. CAD presence, extent, and severity were related to incidence of major adverse cardiovascular event (MACE) by using Cox proportional hazards models. RESULTS: At a mean follow-up of 2.3 years ± 1.2 (standard deviation), MACE occurred in 106 patients. CAD was common for nonobstructive (n = 1452, 27%) and obstructive (n = 629, 12%) CAD. In risk-adjusted analysis, per-patient obstructive CAD (hazard ratio [HR], 6.64; 95% confidence interval [CI]: 3.68, 12.00; P ≤ .001) was related to MACE. MACE was associated with a dose-response relationship to the number of vessels exhibiting obstructive CAD, increasing risk for obstructive one-vessel (HR, 6.11; 95% CI: 3.22, 11.6; P ≤ .001), two-vessel (HR, 5.86; 95% CI: 2.75, 12.5; P ≤ .0001), or three-vessel or left main (HR, 11.69; 95% CI: 5.38, 25.4; P ≤ .001) CAD. The increased hazard for MACE of obstructive disease holds true for symptomatic (HR, 11.9; 95% CI: 4.81, 29.6; P ≤ .001) and asymptomatic (HR, 6.3; 95% CI: 2.4, 16.7; P ≤ .001) patients. No CAD at coronary CT angiography was associated with a low annualized MACE rate: 0.31% versus 2.06% with obstructive disease. CONCLUSION: Among individuals suspected of having CAD but without modifiable risk factors, CAD is common, with significantly increased hazards for MACE and mortality.

Effect of a novel vendor-specific motion-correction algorithm on image quality and diagnostic accuracy in persons undergoing coronary CT angiography without rate-control medications.

BACKGROUND: Although coronary CT angiography (CTA) shows high diagnostic performance for detection and exclusion of obstructive coronary artery disease, limited temporal resolution of current-generation CT scanners may allow for motion artifacts, which may result in nonevaluable coronary segments. OBJECTIVE: We assessed a novel vendor-specific motion-correction algorithm for its effect on image quality and diagnostic accuracy. METHODS: Thirty-six consecutive patients with severe aortic stenosis undergoing coronary CTA without rate control and invasive coronary angiography as part of an evaluation for transcatheter aortic valve replacement. We compared image quality and diagnostic accuracy between standard (STD) and motion-corrected (MC) reconstructions. Coronary CTAs were interpreted in an intent-to-diagnose fashion by 2 experienced readers; a third reader provided consensus for interpretability and obstructive coronary stenosis (≥50% stenosis). All studies were interpreted with and without motion correction using both 45% and 75% of the R-R interval for reconstructions. Quantitative coronary angiography was performed by a core laboratory. RESULTS: Mean age was 83.0 ± 6.4 years; 47% were men. Overall image quality (graded 1-4) was higher with the use of MC versus STD reconstructions (2.9 ± 0.9 vs 2.4 ± 1.0; P < 0.001). MC reconstructions showed higher interpretability on a per-segment [97% (392/406) vs 88% (357/406); P < 0.001] and per-artery [96% (128/134) vs 84% (112/134); P = 0.002] basis, with no difference on a per-patient level [92% (33/36) vs 89% (32/36); P = 1.0]. Diagnostic accuracy by MC reconstruction was higher than STD reconstruction on a per-segment [91% (370/406) vs 78% (317/406); P < 0.001] and per-artery level [86% (115/134) vs 72% (96/134); P = 0.007] basis, with no significant difference on a per-patient level [86% (31/36) vs 69% (25/36); P = 0.16]. CONCLUSIONS: The use of a novel MC algorithm improves image quality, interpretability, and diagnostic accuracy in persons undergoing coronary CTA without rate-control medications.

A proposed clinical model for efficient utilization of invasive coronary angiography.

More than 1/4 of patients who undergo invasive coronary angiography are found to have no visible or nonobstructive (<50% stenosis) coronary artery disease (CAD). With the rapid evolution of noninvasive imaging for CAD diagnosis, avoiding invasive coronary angiography in patients unlikely to require coronary revascularization is desirable. We undertook to develop a clinical prediction tool to identify patients with a low likelihood of obstructive (> or =50% stenosis) CAD. The derivation cohort included 24,637 patients with a diagnosis of "stable angina" or "acute coronary syndrome" referred for first cardiac catheterization in the province of British Columbia, Canada. The model was validated using an external dataset from the province of Alberta and comprised 18,606 patients. Seven variables (female gender, age <50 years, atypical Canadian Cardiovascular Society angina class, absence of ST-segment change on electrocardiogram, lifelong nonsmoking, and absence of diabetes and hyperlipidemia) were associated with the angiographic finding of "no or nonobstructive CAD." The c-statistics for the derivation model were 0.76 and 0.74 using the validation dataset. In conclusion, this simple clinical prediction tool, applied to patients for whom determination of coronary anatomy was clinically indicated, identifies patients who have a low likelihood of obstructive CAD. The patient population identified by this tool may represent a population best suited to a noninvasive diagnostic strategy.

Patient preparation and scanning techniques.

Cardiac computed tomographic angiography (CCTA) is a unique diagnostic modality that can provide a comprehensive assessment of cardiac anatomy. Rapid advances in scanner and software technology have resulted in the ability to noninvasively image the coronary arteries. However, careful patient preparation and scanning technique is required to ensure optimal image quality while minimizing radiation dose delivered. Important components of patient preparation include knowledge of the indications and contraindications for CCTA, patient screening, patient premedication, patient positioning, prescan instruction, and electrocardiograph lead placement. Scanning technique should be determined on a patient by patient basis and tailored according to age and radiation risk, body mass index and chest circumference, heart rate and variability, presence of stents, and coronary calcification.