Skeletal muscle mass is a strong predictor of cardiorespiratory fitness in the Chinese population with obesity

Background and aimsAlthough skeletal muscle is well-known as physiologically related to VO₂max, the independent predictive value of skeletal muscle mass (SMM) VO₂max in people with obesity has not been studied. This study aims to determine the relationships between maximal oxygen uptake (VO₂max) and SMM in the Chinese population with obesity.Methods and resultsOverall, 409 participants with obesity were included in this cross-sectional study. A maximal and graded exercise testing measured VO₂max, and body compositions were measured by bioelectrical impedance analysis. Subsequently, correlation coefficients and stepwise multiple linear regression analyses were used to determine the relationships between VO₂max and body compositions. SMM was found to have a significant correlation with VO₂max (r = 0.290, P < 0.001) after adjusting for sex, age, body mass index (BMI), waist-to-hip ratio, and percent body fat (PBF). In previous studies, BMI was widely recognized as a strong predictor of VO₂max. This study revealed surprising results: after SMM was controlled, the correlation between BMI and VO₂max was reduced (from r = 0.381, P < 0.001 to r = 0.191, P < 0.001). SMM was found the most important independent predictor. In the regression model, the variance of VO₂max was explained by the SMM which accounted for 27.4%.ConclusionsIn summary, SMM is a stronger independent predictor of cardiorespiratory fitness in the Chinese population with obesity than sex, age, BMI, waist-to-hip ratio, and PBF.     

Categorias de Aptidão Física Baseadas no VO2max em População Brasileira com Suposto Alto Nível Socioeconômico e sem Cardiopatia Estrutural

Background The most widely used data for cardiorespiratory fitness (CRF) referrals are from the Cooper Clinic, which uses calculated maximal oxygen uptake (VO₂max) values.Objective To develop CRF values from cardiopulmonary exercise testing (CPX) in a Brazilian population with high socioeconomic level and free of structural heart disease. VO₂max testing results were compared with the Cooper Clinic and FRIEND Registry data.Methods CPX data from consecutive individuals between January 1,2000, and May 31,2016 were used in this study. Inclusion criteria were: VO₂max by a pre-specified definition. We built a CRF chart according to VO₂max percentiles: very poor (≤20%), poor (20-40%), fair (40-60%), good (60-80%), excellent (80-90%), and superior (≥90%). Kappa correlation was used to analyze our data in comparison with that of the other two databases. Statistical tests with p<0.005 were considered significant.Results Final cohort included 18,186 tests: 12,552 men, 5,634 women (7–84 years). The most recurrent response was “good” (20.2%). There was a mean difference in weight, height, body mass index (BMI), and age in the CRF chart. An inverse correlation existed between VO₂max and age, weight, and BMI. Using a linear regression and these variables, a predictive equation was developed for VO₂max. Our findings differed from that of the other databases.Conclusion We developed a classification for CRF and found higher values in all classification ranges of functional capacity in contrast to the Cooper Clinic and FRIEND Registry. Our findings offer a more accurate interpretation of ACR in this large Brazilian population sample when compared to previous standards based on the estimated VO2max. (Arq Bras Cardiol. 2020; 115(3):468-477)     

Cardiac Rehabilitation and Risk of Incident Atrial Fibrillation in Patients With Coronary Artery Disease

BackgroundPatients with coronary artery disease (CAD) are at risk for developing atrial fibrillation (AF). Whether attending a cardiac rehabilitation (CR) program can attenuate this risk is unclear.MethodsThis retrospective cohort study included patients who were free of pre-existing AF and referred to CR after coronary revascularization between April 2004 and March 2015 in Calgary, Canada. Patients with incident AF were identified using administrative data and the local electrocardiogram repository. Exposure variables and covariates were extracted from electronic medical records of a CR program and a clinical registry.ResultsThe study included 11,662 patients (mean age [standard deviation], 60.9 [10.9] years; male, 80.6%). In a median follow-up of 4.8 years, the cumulative incidence rate of AF was 1.04 per 100 person-years. There was no association between completion of CR and the risk of incident AF after adjusting for baseline characteristics (hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.83-1.15). However, each higher metabolic equivalent (MET) of baseline cardiorespiratory fitness (CRF) and each MET gain in CRF following CR were independently associated with a 12% (95% CI, 6%-18%) and 18% (95% CI, 6%-28%) lower relative risk of incident AF, respectively. The risk of incident AF declined progressively, with the baseline CRF increasing up to 9.0 peak METs and with the 12-week CRF increasing up to 10.3 peak METs; beyond these peak MET levels, benefits plateaued.ConclusionsCompletion of CR alone was not associated with a lower risk of incident AF. However, higher baseline CRF and greater CRF improvement had dose-dependent protective effects.     

Low Skeletal Muscle Mass Is Associated With the Presence,Incidence, and Progression of Coronary Artery Calcification

BackgroundLow skeletal muscle mass (SMM) is an emerging risk factor of cardiovascular disease (CVD). We investigated the association between SMM and coronary artery calcification (CAC).MethodsWe enrolled 19,728 adults free of CVD who underwent computed tomographic estimation of Agatston CAC scores for cross-sectional analysis. Among them, 5,401 subjects who had at least 2 follow-up CAC scores were included in longitudinal analysis. Relative SMM is presented as the skeletal muscle mass index [SMI (%) = total appendicular muscle mass (kg)/body weight (kg) × 100]. CAC presence and incidence were defined as CAC score > 0, and CAC progression was defined as √CAC score (follow-up) − √CAC score (baseline) > 2.5.ResultsAmong all of the subjects (mean age 53.4 years, 80.8% male), the prevalence of CAC was 36.7%. The incidence of CAC was 17.4% during a mean of 3.6 years, and the progression of CAC was 49.9% during a mean of 2.3 years. The lowest SMI quartile was significantly associated with an increased risk of CAC presence (adjusted odds ratio 2.75, 95% confidence interval [CI] 2.45-3.05; P < 0.001), incidence (adjusted hazard ratio [AHR] 1.99, 95% CI 1.36-2.91; P < 0.001), and progression (AHR 1.48, 95% CI 1.25-1.77; P < 0.001) compared with the highest quartile. SMI as a continuous value was also significantly inversely associated with CAC. SMI was the best parameter to be related to CAC among other quantitative indices such as height or body mass index adjusted.ConclusionsLow SMM is significantly associated with an elevated risk of CAC, independently of other cardiometabolic parameters.     

Association between cardiorespiratory,muscular fitness and metabolic syndrome in Korean men

AimsCardiorespiratory and muscular fitness (CRF, MF) are independent predictor of metabolic syndrome (MS). The purpose of this study was to investigate the association between CRF, MF and MS in male adults.MethodsData collected from 10,774 males who visited the National Fitness Center between 2002 and 2009. The data included measurements of subjects' blood pressure, HDL-cholesterol, triglycerides, body mass index, CRF (VO₂max), MF (grip strength, push-up, sit-up, knee joint strength). CRF, MF level was classified into three tertiles.ResultsAs for the prevalence rate according to CRF level, the differences between groups were 47.6% of the low CRF group, 33.1% of the middle CRF group, and 19.3% of the high CRF group were found to have MS. As for the MS prevalence rate according to MF level, the differences between groups were 47.1% of the low, 31.8% of the middle, 21.1% of the high MF group were found to MS. It was found that MS odds ratios (OR, 95% confidence interval) decreased as the CRF levels improved; as indicated by OR = 0.64 (0.57–0.72) in the middle CRF, OR = 0.36 (0.31–0.41) in the high CRF. As for MF, the middle MF, OR = 0.62 (0.55–0.70), the high MF, OR = 0.40 (0.35–0.45) were lower than that of the low MF.ConclusionThe level of CRF, MF has association with MS in men. This study suggests that we need to manage our fitness to prevent MS.     

Prevalence of atrial fibrillation dependent on coronary artery status: Insights from the LIFE-Heart Study

BackgroundCoronary artery disease (CAD) is a significant risk factor for atrial fibrillation (AF). Experimental studies demonstrated that atrial ischemia induced by right coronary artery (RCA) stenosis promote AF triggers and development of electro‐anatomical substrate for AF.AimTo analyze the association between AF prevalence and coronary arteries status in the LIFE‐Heart Study.MethodsThis analysis included patients with available coronary catheterization data recruited between 2006 and 2014. Patients with acute myocardial infarction were excluded. CAD was defined as stenosis ≥75%, while coronary artery sclerosis (CAS) was defined as non‐critical plaque(s) <75%.ResultsIn total, 3.458 patients (median age 63 years, 34% women) were included into analysis. AF was diagnosed in 238 (6.7%) patients. There were 681 (19.7%) patients with CAS and 1.411 (40.8%) with CAD (27.5% with single, 32.4% with double, and 40.1% with triple vessel CAD). In multivariable analysis, there was a significant association between prevalent AF and coronary artery status (OR 0.64, 95% CI 0.53‐0.78, P _trend < .001). Similarly, AF risk was lower in patients with higher CAD extent (OR 0.54, 95%CI 0.35‐0.83, P _trend = .005). Compared to single vessel CAD, the risk of AF was lower in double (OR 0.42, 95%CI 0.19‐0.95, P = .037) and triple CAD (OR 0.31, 95%CI 0.13‐0.71, P = .006). Finally, no association was found between AF prevalence and CAD origin among patients with single vessel CAD.ConclusionIn the LIFE‐Heart Study, CAS but not CAD was associated with increased risk of AF.     

Diagnostic performance of 320-slice computed tomography coronary angiography for symptomatic patients in clinical practice

ObjectiveMulti-slice computed tomography (MSCT) coronary angiography has been reported as an effective alternative to invasive conventional coronary angiography (CCA) for the diagnosis of coronary artery disease (CAD). However, in previous reports, the diagnostic accuracy of MSCT has not been significant enough to be of benefit in symptomatic patients. The aim of this study was to identify the usefulness of 320-slice computed tomography coronary angiography (320-CTA) for symptomatic patients in terms of the diagnostic accuracy of 320-CTA and the prevalence of vasospastic angina pectoris (VSAP) within the study cohort.MethodsWe retrospectively analyzed 513 consecutive symptomatic patients with suspected CAD who had undergone 320-CTA and CCA. We determined the diagnostic accuracy of 320-CTA using CCA as the reference standard. Ergonovine provocation tests were performed on patients without significant coronary artery stenosis on CCA.ResultsOf the total cohort of 513 symptomatic patients, 39% had obstructive CAD. The patient based analysis of the accuracy of 320-CTA showed a sensitivity of 91.0%, a specificity of 71.0%, a positive predictive value of 66.5%, and a negative predictive value of 92.5%. Of the 314 symptomatic patients who did not have significant coronary artery stenosis on CCA, 58 (18%) were diagnosed with VSAP using ergonovine provocation tests.DiscussionThe negative and positive predictive values indicate that 320-CTA cannot replace CCA for symptomatic patients. Indeed, a combination of CCA and ergonovine provocation tests should be taken into consideration for symptomatic patients.     

Influence of age in estimating maximal oxygen uptake

Objective To assess the influence of age on the error of estimate (EE) of maximal oxygen uptake (VO₂max) using sex and population specific-equations in cycle ergometer exercise testing, since estimated VO₂max is associated with a substantial EE, often exceeding 20%, possibly due to intrinsic variability of mechanical efficiency. Methods 1850 adults (68% men), aged 18 to 91 years, underwent maximal cycle ergometer cardiopulmonary exercise testing. Cardiorespiratory fitness (CRF) was assessed relative to sex and age [younger (18 to 35 years), middle-aged (36 to 60 years) and older (> 60 years)]. VO₂max [mL?(kg?min)^?1] was directly measured by assessment of gas exchange and estimated using sex and population specific-equations. Measured and estimated values of VO₂max and related EE were compared among the three age- and sex-specific groups. Results Directly measured VO₂max of men and women were 29.5 ± 10.5 mL?(kg?min)^?1 and 24.2 ± 9.0 mL?(kg?min)^?1 (P < 0.01). EE [mL?(kg?min)^?1] and percent errors (%E) for men and women had similar values, 0.5 ± 3.2 and 0.4 ± 2.9 mL?(kg?min)^?1, and ?0.8 ± 13.1% and ?1.7 ± 15.4% (P > 0.05), respectively. EE and %E for each age-group were, respectively, for men: younger = 1.9 ± 4.1 mL?(kg?min)^?1 and 3.8 ± 10.5%, middle-aged = 0.6 ± 3.1 mL?(kg?min)^?1 and 0.4 ± 10.3%, older = ?0.2 ± 2.7 mL?(kg?min) ^?1 and ?4.2 ± 16.6% (P < 0.01); and for women: younger = 1.2 ± 3.1 mL?(kg?min) ^?1 and 2.7 ± 10.0%, middle-aged = 0.7 ± 2.8 mL?(kg?min)?1 and 0.5 ± 11.1%, older = -0.8 ± 2.3 mL?(kg?min)^?1 and ?9.5 ± 22.4% (P < 0.01). Conclusion VO₂max were underestimated in younger age-groups and were overestimated in older age groups. Age significantly influences the magnitude of the EE of VO₂max in both men and women and should be considered when CRF is estimated using population specific equations, rather than directly measured.     

The importance of characteristics of angina symptoms for the prediction of coronary artery disease in a cohort of stable patients in the modern era

ObjectiveAngina is an important clinical symptom indicating underlying coronary artery disease (CAD). Its characteristics are important for the diagnosis and risk stratification of patients with CAD. Currently, we aimed to investigate the association of chest pain characteristics with the presence of obstructive CAD in a contemporary cohort of patients undergoing coronary angiography for suspected stable CAD.MethodsConsecutive patients undergoing coronary angiography for suspected stable CAD (n = 686) in a single university hospital cardiology department were enrolled. Chest pain was classified as typical angina, atypical angina, nonangina chest pain, and lack of symptoms. The presence of significant angiographic CAD was diagnosed by standard coronary angiography.ResultsTypical angina symptoms were associated with a higher prevalence of CAD (odds ratio [OR], 3.47, p < 0.001), whereas atypical angina symptoms were associated with a lower prevalence of CAD (OR, 0.49, p = 0.003) than the nonangina symptoms/or asymptomatic status. In multivariate analysis, typical angina symptoms remained an independent predictor of CAD (OR, 2.54, p < 0.001), with a greater predictive accuracy than other clinical risk factors (area under the curve [AUC], 0.715, p < 0.001) and similar to the accuracy of the high-sensitivity C-reactive protein (AUC, 0.712, p < 0.001). In a multivariate model, the combination of all studied factors further improved the predictive accuracy (AUC, 0.81, p < 0.001).ConclusionIn a contemporary cohort of patients referred for coronary angiography for stable CAD, the presence of typical angina symptoms was the most important independent predictor of obstructive CAD. The association of atypical angina symptoms with low CAD prevalence compared to nonangina chest pain or absence of significant symptoms probably reflects different management and referral strategies in these groups of patients.     

Systematic re-evaluation of the diagnosis and treatment of coronary artery disease in hospitalized elderly: Impact on medication underuse. The multicenter IRIDIA study

Despite benefit of secondary prevention of coronary artery disease, evidence-based treatment are underused in very elderly patients. The objective of IRIDIA study is to evaluate feasibility of improving on the use of coronary artery disease evidence-based therapies through a intervention, based on diagnosis and treatment reassessment, in elderly inpatients.MethodsDesign: prospective cohort study with one-year follow-up. Setting: six acute care geriatric wards in France. Participants: consecutive inpatients ≥ 75 years old with a supposed diagnosis of coronary artery disease (CAD).InterventionFirst step: reassessment of CAD diagnosis using coronary-oriented investigations. Second step: optimization of CAD treatment in accordance with international guidelines. Primary outcome: change in use of the recommended CAD treatment between admission and discharge. Secondary outcome: diagnosis optimization between admission and discharge.ResultsTwo hundred and sixty-one participants (mean age 87 years [IQR: 83–92 years]) with a high prevalence of comorbidities, cognitive impairment, and disability. The CAD diagnosis was considered confirmed at inclusion in 138 of the 261 patients (53%) with an evident underuse of β-blockers and antiplatelet agents. The impact of the intervention on CAD diagnosis was 40%; for 74 patients, the diagnosis remained uncertain. For patients with confirmed CAD (n = 178), the treatment optimization resulted in a increase in use of evidence-based therapy, with rates of 66% for β-blockers and 79% for antiplatelet agents, without significant complications at 1 year.ConclusionThis multicenter study demonstrated the feasibility of improving on the use of CAD evidence-based therapies through a simple intervention, including CAD diagnosis optimization and treatment reassessment, in a very elderly population with comorbidities in an acute-care setting.Trial registrationClinical Trials. gov Identifier: NCT00224575.     

Relationship between arterial stiffness parameters and the extent and severity of coronary artery disease

BackgroundThe association between arterial stiffness (AS) and coronary artery disease (CAD) has been previously demonstrated. In the present study, we aim to investigate the relationship between various AS parameters and the extent and severity of CAD.MethodsThe study population consisted of 411 patients with CAD documented by coronary angiography. We measured various AS parameters including augmentation index (AIx), augmentation pressure (AP), pulse wave velocity (PWV), central systolic pressure (cSys), central diastolic pressure (cDia) and central pulse pressure (cPP) with pulse wave analysis. Angiographic images were used to calculate Gensini score and Syntax score. AS parameters were compared using Gensini score and Syntax score.ResultsSyntax score is correlated with age, cSys, cPP, PWV, AP, brachial pulse pressure (bPP), hemoglobin, urea, diabetes mellitus, left main coronary artery disease (p < 0.10 for each). However, Gensini score is correlated only with age, diabetes mellitus, left main coronary artery disease and bPP (p < 0.10 for each). Multivariate analysis revealed age, diabetes mellitus, left main coronary artery disease and bPP as significant predictors of Syntax score; however, for Gensini score, age, diabetes mellitus, gender, left main coronary artery disease, and bPP are determined as predictors.ConclusionAS parameters are not associated with Syntax score or Gensini score. Apart from traditional risk factors, bPP appears to be the only significant predictor for Syntax score and Gensini score.     

Non-diabetic hyperglycaemia correlates with angiographic coronary artery disease prevalence and severity

AimThe role of glycaemia as a coronary artery disease (CAD) risk factor is controversial, and the optimal glucose level is still a matter of debate. For this reason, we assessed the prevalence and severity of angiographic CAD across hyperglycaemia categories and in relation to haemoglobin A_1c (HbA_1c) levels.MethodsWe studied 273 consecutive patients without prior revascularization undergoing coronary angiography for suspected ischaemic pain. CAD severity was assessed using three angiographic scores: the Gensini's score; extent score; and arbitrary index. Patients were grouped, according to 2003 American Diabetes Association criteria, into those with normal fasting glucose (NFG), impaired fasting glucose (IFG) and diabetes mellitus (DM).ResultsCAD prevalence was 2.5-fold higher in both the IFG and DM groups compared with the NFG group. Deterioration of glycaemic profile was a multivariate predictor of angiographic CAD severity (extent score: P = 0.027; arbitrary index: P = 0.007). HbA_1c levels were significantly higher among CAD patients (P = 0.016) and in those with two or more diseased vessels (P = 0.023) compared with the non-CAD group. HbA_1c levels remained predictive of CAD prevalence even after adjusting for conventional risk factors, including DM (adjusted OR: 1.853; 95% CI: 1.269–2.704).ConclusionNon-diabetic hyperglycaemia, assessed either categorically by fasting glucose categories or continuously by HbA_1c levels, correlates with the poorest angiographic outcomes.     

The Association between the Change in Directly Measured Cardiorespiratory Fitness across Time and Mortality Risk

BackgroundThe relationship between cardiorespiratory fitness (CRF) and mortality risk has typically been assessed using a single measurement, though some evidence suggests the change in CRF over time influences risk. This evidence is predominantly based on studies using estimated CRF (CRF_e). The strength of this relationship using change in directly measured CRF over time in apparently healthy men and women is not well understood.PurposeTo examine the association of change in CRF over time, measured using cardiopulmonary exercise testing (CPX), with all-cause and disease-specific mortality and to compare baseline and subsequent CRF measurements as predictors of all-cause mortality.MethodsParticipants included 833 apparently healthy men and women (42.9 ± 10.8 years) who underwent two maximal CPXs, the second CPX being ≥1 year following the baseline assessment (mean 8.6 years, range 1.0 to 40.3 years). Participants were followed for up to 17.7 (SD 11.8) years for all-cause-, cardiovascular disease- (CVD), and cancer mortality. Cox-proportional hazard models were performed to determine the association between the change in CRF, computed as visit 1 (CPX1) peak oxygen consumption (VO_2peak [mL·kg⁻¹·min⁻¹]) – visit 2 (CPX2) VO_2peak, and mortality outcomes. A Wald-Chi square test of equality was used to compare the strength of CPX1 to CPX2 VO_2peak in predicting mortality.ResultsDuring follow-up, 172 participants died. Overall, the change in CPX-CRF was inversely related to all-cause, CVD, and cancer mortality (p < 0.05). Each 1 mL·kg⁻¹·min⁻¹ increase was associated with a ~11, 15, and 16% (all p < 0.001) reduction in all-cause, CVD, and cancer mortality, respectively. The inverse relationship between CRF and all-cause mortality was significant (p < 0.05) when men and women were examined independently, after adjusting for years since first CPX, baseline VO_2peak, and age. Further, the Wald Chi-square test of equality found CPX2 VO_2peak to be a significantly stronger predictor of all-cause mortality than CPX1 VO_2peak (p < 0.05).ConclusionThe change in CRF over time was inversely related to mortality outcomes, and mortality was better predicted by CRF measured at subsequent test than CPX1 CRF. These findings emphasize the importance of adopting lifestyle behaviors that promote CRF, as well as support the need for routine assessment of CRF in clinical practice to better assess risk.     

Diagnostic Yield of Coronary Angiography in Asymptomatic Orthotopic Liver Transplantation Candidates

BackgroundThe ideal cardiac risk stratification strategy for orthotopic liver transplantation (OLT) is unknown. Our institution performed coronary angiography for asymptomatic OLT candidates at high risk for CAD: ≥65 years of age, diabetic and ≥55 years of age or diagnosed ≥5 years, abnormal stress test, or at the discretion of the OLT committee.MethodsThe analysis included 301 consecutive, asymptomatic OLT candidates who underwent coronary angiography. The primary outcome was the prevalence of obstructive CAD.ResultsAt 2-year follow-up, OLT was performed in 44.9%, and 42.2% died. The prevalence of obstructive CAD, involvement of the proximal or mid LAD, and 3-vessel CAD were 10.3%, 6.6%, and 0.7%, respectively. Percutaneous and surgical revascularization were performed in 7.0% and 1.3%, respectively. Stress test was performed in 54.8%. The sensitivity and specificity of stress testing were 0% and 87.1%, respectively. The negative and positive predictive values of stress testing were 91.4% and 0%, respectively. Chest computed tomography (CT) was performed in 83.1%. Moderate or severe coronary artery calcification (CAC) was present in 47.8%. The sensitivity and specificity of moderate or severe CAC were 88.9% and 57.3%, respectively. The negative and positive predictive values of moderate or severe CAC were 97.7% and 20.2%, respectively. Multivariate analysis demonstrated that CAC was an independent predictor of obstructive CAD (HR 10.7; 95% CI 3.2–37.9; p < 0.001).ConclusionsThe prevalence of obstructive CAD in asymptomatic OLT candidates at high risk was uncommon. Alternative diagnostic strategies may be preferred to coronary angiography.     

Coronary atherosclerotic burden in veteran male recreational athletes with low to intermediate cardiovascular risk

IntroductionAlthough there is evidence that a significant proportion of veteran athletes have coronary atherosclerotic disease (CAD), its prevalence in recreational athletes with low to intermediate cardiovascular (CV) risk is not established. This study aimed to characterize the coronary atherosclerotic burden in veteran male recreational athletes with low to intermediate CV risk.MethodsAsymptomatic male athletes aged ≥40 years with low to intermediate risk, who exercised >4 hours/week for >5 years, underwent cardiac computed tomography (CT) for coronary artery calcium (CAC) scoring and CT angiography. High coronary atherosclerotic burden was defined as at least one of the following: CAC score >100; CAC score ≥75th percentile; obstructive CAD; disease involving the left main, three vessels or two vessels including the proximal left anterior descending artery; segment involvement score >5; or CT Leaman score ≥5. Athletes were categorized by tertiles of exercise volume, calculated by metabolic equivalent of task (MET) scores.ResultsA total of 105 athletes were included, all with SCORE <4%, mainly engaged in high-dynamic sports. Median exercise volume was 66 (44-103) METs/hour/week, with 8±5 hours training/week and 17±10 years of exercise. A high coronary atherosclerotic burden was present in 27 (25.7%) athletes. Ten (9.5%) athletes had CAC score >100, 13 (12.4%) had CAC score ≥75th percentile and six (5.7%) had obstructive lesions. The extent and severity of coronary plaques did not differ according to exercise volume.ConclusionsThe prevalence of subclinical CAD detected by cardiac CT in veteran male recreational athletes with low to intermediate CV risk was high. Up to a quarter of our cohort had a high coronary atherosclerotic burden.     

Reduction of submaximal exercise myocardial oxygen demand post-walk training program in coronary patients due to improved physical work efficiency

To assess the effects of walk training on external work efficiency and the determinants of myocardial oxygen demand (MVO₂), we measured total somatic oxygen consumption (VO₂), heart rate (HR), and systolic blood pressure (SBP) in eight male coronary (CAD) patients during submaximal treadmill walking before and after at least 14 weeks of prescribed exercise. Each patient was tested before and after training at the individually determined horizontal treadmill speed that induced ischemic ST segment depression in the pretraining test. Although maximal oxygen uptake (VO₂ max) did not increase significantly with training, submaximal exercise HR and the product of HR and SBP were significantly (p < 0.05) reduced by 10% (120 → 108/min) and 16% (185 × 10² → 156 × 10²), respectively, and none of the patients had ischemic ECG changes after training. The reductions in the cardiac response to exercise were due primarily to a 10% decrease (18.9 → 17.1 ml/kg/min, p < 0.05) in somatic oxygen requirements (VO₂), indicating that the patients became more efficient walkers and reduced their MVO₂ in proportion to the decreased total VO₂. Thus, enhancement of external work efficiency, an extracardiac factor, can lessen myocardial energy costs (MVO₂) and thereby raise the exercise threshold for cardiac ischemia in CAD patients even when aerobic capacity (VO₂ max) is not increased.     

O Teste do Degrau de Seis Minutos como Preditor de Capacidade Funcional de Acordo com o Consumo de Oxigênio de Pico em Pacientes Cardíacos

Background:Six-minute step test (6MST) is a simple way to evaluate functional capacity, although it has not been well studied in patients with coronary artery disease (CAD) or heart failure (HF).Objective:Analyze the association between the 6MST and peak oxygen uptake (VO_2peak) and develop an equation for estimating VO_2peak based on the 6MST, as well as to determine a cutoff point for the 6MST that predicts a VO_2peak ≥20 mL.Kg^-1.min^-1Methods:In 171 patients who underwent the 6MST and a cardiopulmonary exercise test, correlation, regression, and ROC analysis were used and a p < 0.05 was admitted as significant.Results:mean age was 60±14 years and 74% were male. Mean left ventricle ejection fraction was 57±16%, 74% had CAD and 28% had HF. Mean VO_2peak was 19±6 mL.Kg^-1.min^-1 and mean 6MST performance was 87±45 steps. Association between 6MST and VO_2peak was r 0.69 (p <0.001). The model VO_2peak =19.6 + (0.075 x 6MST) – (0.10 x age) for men and VO_2peak =19.6 + (0.075 x 6MST) – (0.10 x age) – 2 for women could predict VO_2peak based on 6MST results (adjusted R 0.72; adjusted R² 0.53). The most accurate cutoff point for 6MST to predict a VO_2peak ≥20 mL.Kg^-1.min^-1 was >105 steps (AUC 0.85; 95% CI 0.79 -0.90; p <0.001).Conclusion:An equation for predicting VO_2peak based on 6MST results was derived, and a significant association was found between 6MST and VO_2peak. The cutoff point for 6MST, which predicts a VO_2peak ≥20 mL.Kg^-1.min^-1, was >105 steps. (Arq Bras Cardiol. 2021; 116(5):889-895)     

The report of male gender and retinopathy status improves the current consensus guidelines for the screening of myocardial ischemia in asymptomatic type 2 diabetic patients

Background and aimsAmerican Diabetes Association (ADA), French-speaking Societies for diabetes & cardiology (ALFEDIAM-SFC) and Cardiac Radionuclide Imaging (CRI) have proposed guidelines for the screening of silent myocardial ischemia (SMI). The aim of the study was to evaluate their diagnostic values and how to improve them.Methods and results731 consecutive type 2 diabetic patients with ≥1 additional risk factor were screened between 1992 and 2006 for SMI by stress myocardial scintigraphy and for silent coronary artery disease (CAD) by coronary angiography. A total of 215 (29.4%) patients had SMI, and 79 of them had CAD. ADA (Odds Ratio 1.7 [95% Confidence Interval: 1.2–2.5]; p < 0.05), ALFEDIAM-SFC (OR 1.5 [1.0–2.5], p < 0.05) and CRI criteria (OR 2.0 [1.4–2.8], p < 0.01) predicted SMI. Considering the presence of male gender and retinopathy added to the prediction of SMI allowed by ADA criteria (c statistic: area under the curve AROC 0.651 [0.605–0.697] versus 0.582 [0.534–0.630]), p < 0.01 and ALFEDIAM-SFC criteria (AROC 0.672 [0.620–0.719] versus 0.620 [0.571–0.670], p < 0.05). CRI prediction of SMI was improved by considering the presence of macroproteinuria and retinopathy (AROC 0.621 [0.575–0.667] versus 0.594 [0.548–0.641], p < 0.01). Severe retinopathy (OR 3.4 [1.2–9.4], p < 0.05), smoking habits (OR 2.1 [1.1–4.2], p < 0.05) and triglyceride levels (OR 1.3 [1.0–1.6], p < 0.05) were independent predictors of CAD in the patients with SMI.ConclusionCurrent guidelines criteria are able to predict SMI but prediction may be improved by considering male gender and the presence of retinopathy. CAD is more frequent in the patients with SMI who are current smokers, have severe retinopathy and higher triglyceride levels.     

Myocardial ischemia: a silent epidemic in Type 2 diabetes patients

The prevalence of diabetes mellitus is increasing consistently. Coronary artery disease (CAD) is the main cause of death; however, silent myocardial ischemia (SMI) is more frequent in diabetic patients. Early CAD diagnosis provided by SMI screening could lead to decreased cardiovascular complications and mortality. Current guidelines recommend screening for SMI in asymptomatic diabetic patients selected on a basis of high cardiovascular risk, followed by coronary angiogram in case of a positive stress test. However, the benefit of systematic SMI screening has not been demonstrated in diabetic patients with optimal treatment of risk factors. The benefit of revascularization in diabetic patients with SMI seems to be restricted to patients with severe CAD. Prospective studies are required to identify diabetic patients who may potentially benefit from SMI screening. These patients should have a high prevalence of severe CAD and potential benefit of revascularization, such as patients with renal failure, left ventricular dysfunction and peripheral or carotid occlusive arterial disease.