Exertional breathlessness related to medical conditions in middle-aged people: the population-based SCAPIS study of more than 25,000 men and women

BACKGROUND

Breathlessness is common in the population and can be related to a range of medical conditions. We aimed to evaluate the burden of breathlessness related to different medical conditions in a middle-aged population.

METHODS

Cross-sectional analysis of the population-based Swedish CArdioPulmonary bioImage Study of adults aged 50-64 years. Breathlessness (modified Medical Research Council [mMRC] ≥ 2) was evaluated in relation to self-reported symptoms, stress, depression; physician-diagnosed conditions; measured body mass index (BMI), spirometry, venous haemoglobin concentration, coronary artery calcification and stenosis [computer tomography (CT) angiography], and pulmonary emphysema (high-resolution CT). For each condition, the prevalence and breathlessness population attributable fraction (PAF) were calculated, overall and by sex, smoking history, and presence/absence of self-reported cardiorespiratory disease.

RESULTS

We included 25,948 people aged 57.5 ± [SD] 4.4; 51% women; 37% former and 12% current smokers; 43% overweight (BMI 25.0-29.9), 21% obese (BMI ≥ 30); 25% with respiratory disease, 14% depression, 9% cardiac disease, and 3% anemia. Breathlessness was present in 3.7%. Medical conditions most strongly related to the breathlessness prevalence were (PAF 95%CI): overweight and obesity (59.6-66.0%), stress (31.6-76.8%), respiratory disease (20.1-37.1%), depression (17.1-26.6%), cardiac disease (6.3-12.7%), anemia (0.8-3.3%), and peripheral arterial disease (0.3-0.8%). Stress was the main factor in women and current smokers.

CONCLUSION

Breathlessness mainly relates to overweight/obesity and stress and to a lesser extent to comorbidities like respiratory, depressive, and cardiac disorders among middle-aged people in a high-income setting-supporting the importance of lifestyle interventions to reduce the burden of breathlessness in the population.

Percent predicted peak oxygen uptake is superior to weight-indexed peak oxygen uptake in risk stratification before lung cancer lobectomy

OBJECTIVE

To improve preoperative risk stratification in lung cancer lobectomy by identifying and comparing optimal thresholds for peak oxygen uptake (VO2peak) presented as weight-indexed and percent of predicted values, respectively.

METHODS

This was a longitudinal cohort study including national registry data on patients scheduled for cancer lobectomy that used available data from preoperative cardiopulmonary exercise testing. The measured VO2peak was indexed by body mass (mL/kg/min) and also compared with 2 established reference equations (Wasserman-Hansen and Study of Health in Pomerania, respectively). By receiver operating characteristic analysis, a lower 90% specificity and an upper 90% sensitivity threshold were determined for each measure, in relation to the outcome of any major complication or death. For each measure and based on these thresholds, patients were categorized as low risk, intermediate risk, or high risk. The frequency of complications was compared between groups using χ2.

RESULTS

The frequency of complications differed significantly between the proposed low-, intermediate-, and high-risk groups when using % predicted Study of Health in Pomerania (5%, 21%, 35%, P = .007) or % predicted Wasserman-Hansen (5%, 25%, 35%, P = .002) but not when using the weight-indexed VO2peak groups (7%, 23%, 15%, P = .08). Nonsignificant differences were found using the threshold <15 mL/kg/min (P = .34).

CONCLUSIONS

This study showed that weight-indexed VO2peak was of less use as a marker of risk at the lower range of exercise capacity, whereas % predicted VO2peak was associated with a continuously increasing risk of major complications, also at the lower end of exercise capacity. As identifying subjects at high risk of complications is important, % predicted VO2peak is therefore preferable.

Physical fitness in male adolescents and atherosclerosis in middle age: a population-based cohort study

OBJECTIVES

To examine the associations between physical fitness in male adolescents and coronary and carotid atherosclerosis in middle age.

METHODS

This population-based cohort study linked physical fitness data from the Swedish Military Conscription Register during adolescence to atherosclerosis data from the Swedish CArdioPulmonary bioImage Study in middle age. Cardiorespiratory fitness was assessed using a maximal cycle-ergometer test, and knee extension muscular strength was evaluated through an isometric dynamometer. Coronary atherosclerosis was evaluated via Coronary Computed Tomography Angiography (CCTA) stenosis and Coronary Artery Calcium (CAC) scores, while carotid plaques were evaluated by ultrasound. The associations were analysed using multinomial logistic regression, adjusted (marginal) prevalences and restricted cubic splines.

RESULTS

The analysis included 8986 male adolescents (mean age 18.3 years) with a mean follow-up of 38.2 years. Physical fitness showed a reversed J-shaped association with CCTA stenosis and CAC, but no consistent association was observed for carotid plaques. After adjustments, compared with adolescents in the lowest tertile of cardiorespiratory fitness and muscular strength, those in the highest tertile had 22% (OR 0.78; 95% CI 0.61 to 0.99) and 26% (OR 0.74; 95% CI 0.58 to 0.93) lower ORs for severe (≥50%) coronary stenosis, respectively. The highest physical fitness group (high cardiorespiratory fitness and muscular strength) had 33% (OR 0.67; 95% CI 0.52 to 0.87) lower OR for severe coronary stenosis compared with those with the lowest physical fitness.

CONCLUSION

This study supports that a combination of high cardiorespiratory fitness and high muscular strength in adolescence is associated with lower coronary atherosclerosis, particularly severe coronary stenosis, almost 40 years later.

VE/VCO2 slope threshold optimization for preoperative evaluation in lung cancer surgery: identifying true high- and low-risk groups

Background

Cardiopulmonary exercise testing (CPET) enables measurement of the slope of the increase in minute ventilation in relation to carbon dioxide elimination during exercise (the VE/VCO2 slope). Several studies have shown that the VE/VCO2 slope is a strong marker for postoperative complications and mortality. However, current thresholds for adverse outcomes are generated from historical data in heart failure patients.

Methods

This was a retrospective analysis of 158 patients with lung cancer who underwent lobectomy or pneumonectomy during 2008-2020. The main outcome was major pulmonary complications (MPC) or death ≤30 days of cancer surgery. Patients were first categorized using two different single threshold approaches; the traditional threshold of 35 and the highest Youden value from the receiver operating curve (ROC) analysis. Secondly, patients were categorized into three risk groups using two thresholds. These two thresholds were determined in an ROC analysis, where the VE/VCO2 slope values generating either a 90% sensitivity (lower threshold) or a 90% specificity (upper threshold) for the main outcome were chosen. The frequency of complications was compared using Chi2. The overall model quality was evaluated by an area under the curve (AUC) analysis. Positive predictive values (PPVs) and negative predictive values (NPVs) are presented.

Results

The two thresholds, <30 (90% sensitivity) and >41 (90% specificity), created three risk groups: low risk (VE/VCO2 slope <30, n=44, 28%); intermediate risk (VE/VCO2 slope 30-41, n=95, 60%) and high risk (VE/VCO2 slope >41, n=19, 12%). The frequency of complications differed between groups: 5%, 16% and 47% (P<0.001). Using two thresholds compared to one threshold increased the overall model quality (reaching AUC 0.70, 95% confidence interval: 0.59-0.81), and identified a high sensitivity threshold (VE/VCO2 slope <30) which generated a NPV of 95% but importantly, also a high specificity threshold (VE/VCO2 slope >41) with a PPV of 47%.

Conclusions

Risk stratification based on three risk groups from the preoperative VE/VCO2 slope increased the model quality, was more discriminative and generated better PPV and NPV compared to traditional risk stratification into two risk groups.

Exercise Systolic Blood Pressure Response During Cycle Ergometry is Associated with Future Hypertension in Normotensive Individuals

AIMS

We aimed to investigate the association between the exercise systolic blood pressure (SBP) response and future hypertension (HTN) in normotensive individuals referred for cycle ergometry, with special regard to reference exercise SBP values, and exercise capacity.

METHODS

In this longitudinal cohort study, data from 14,428 exercise tests were cross-linked with Swedish national registries on diagnoses and medications. We excluded individuals with a baseline diagnosis of cardiovascular disease or HTN. The peak exercise SBP (SBPpeak) was recorded and compared to the upper limit of normal (ULN) derived from SBPpeak reference equations incorporating age, sex, resting SBP and exercise capacity. To evaluate the impact of exercise capacity, three SBP to work rate slopes (SBP/W-slopes), were calculated, relative to either supine or seated SBP at rest or to the first exercise SBP. Adjusted hazard ratios (HRadjusted [95% Confidence interval, CI]) for incident HTN during follow-up, in relation to SBP response metrics, were calculated.

RESULTS

We included 3,895 normotensive individuals (49±14 years, 45% females) with maximal cycle ergometer tests. During follow-up (median 7.5 years) 22% developed HTN. Higher SBPpeak and SBPpeak>ULN were associated with incident HTN (HRadjusted 1.19 [1.14-1.23] per 10 mmHg, and 1.95 [1.54-2.47], respectively). All three SBP/W-slopes were positively associated to incident HTN, particularly the SBP/W-slope calculated as supine-to-peak SBP (HRadjusted 1.25 [1.19-1.31] per 1 mmHg/10W).

CONCLUSION

Both SBPpeak>ULN based on reference values and high SBP/W-slopes were associated with incident HTN in normotensive individuals and should be considered in the evaluation of the cycle ergometry SBP response.

Peak oxygen uptake in combination with ventilatory efficiency improve risk stratification in major abdominal surgery

This pilot study aimed to evaluate if peak VO2 and ventilatory efficiency in combination would improve preoperative risk stratification beyond only relying on peak VO2 . This was a single-center retrospective cohort study including all patients who underwent cardiopulmonary exercise testing (CPET) as part of preoperative risk evaluation before major upper abdominal surgery during years 2008-2021. The primary outcome was any major cardiopulmonary complication during hospitalization. Forty-nine patients had a preoperative CPET before decision to pursue to surgery (cancer in esophagus [n = 18], stomach [6], pancreas [16], or liver [9]). Twenty-five were selected for operation. Patients who suffered any major cardiopulmonary complication had lower ventilatory efficiency (i.e., higher VE/VCO2 slope, 37.3 vs. 29.7, p = 0.031) compared to those without complications. In patients with a low aerobic capacity (i.e., peak VO2  < 20 mL/kg/min) and a VE/VCO2 slope ≥ 39, 80% developed a major cardiopulmonary complication. In this pilot study of patients with preoperative CPET before major upper abdominal surgery, patients who experienced a major cardiopulmonary complication had significantly lower ventilatory efficiency compared to those who did not. A low aerobic capacity in combination with low ventilatory efficiency was associated with a very high risk (80%) of having a major cardiopulmonary complication.

Cardiorespiratory dysautonomia in post-COVID-19 condition: Manifestations, mechanisms and management

A significant proportion of COVID-19 patients experience debilitating symptoms for months after the acute infection. According to recent estimates, approximately 1 out of 10 COVID-19 convalescents reports persistent health issues more than 3 months after initial recovery. This 'post-COVID-19 condition' may include a large variety of symptoms from almost all domains and organs, and for some patients it may mean prolonged sick-leave, homestay and strongly limited activities of daily life. In this narrative review, we focus on the symptoms and signs of post-COVID-19 condition in adults - particularly those associated with cardiovascular and respiratory systems, such as postural orthostatic tachycardia syndrome or airway disorders - and explore the evidence for chronic autonomic dysfunction as a potential underlying mechanism. The most plausible hypotheses regarding cellular and molecular mechanisms behind the wide spectrum of observed symptoms - such as lingering viruses, persistent inflammation, impairment in oxygen sensing systems and circulating antibodies directed to blood pressure regulatory components - are discussed. In addition, an overview of currently available pharmacological and non-pharmacological treatment options is presented.

Cardiorespiratory fitness components in relation to clinical characteristics, disease state and medication intake: A patient registry study

BACKGROUND

Interpretation of cardiopulmonary exercise testing (CPET) results requires thorough understanding of test confounders such as anthropometrics, comorbidities and medication. Here, we comprehensively assessed the clinical determinants of cardiorespiratory fitness and its components in a heterogeneous patient sample.

METHODS

We retrospectively collected medical and CPET data from 2320 patients (48.2% females) referred for cycle ergometry at the University Hospital Leuven, Belgium. We assessed clinical determinants of peak CPET indexes of cardiorespiratory fitness (CRF) and its hemodynamic and ventilatory components using stepwise regression and quantified multivariable-adjusted differences in indexes between cases and references.

RESULTS

Lower peak load and peak O2 uptake were related to: higher age, female sex, lower body height and weight, and higher heart rate; to the intake of beta blockers, analgesics, thyroid hormone replacement and benzodiazepines; and to diabetes mellitus, chronic kidney disease, non-ST elevation myocardial infarction and atrial fibrillation (p < 0.05 for all). Lower peak load also correlated with obstructive pulmonary diseases. Stepwise regression revealed associations of hemodynamic and ventilatory indexes (including heart rate, O2 pulse, systolic blood pressure and ventilation at peak exercise and ventilatory efficiency) with age, sex, body composition and aforementioned diseases and medications. Multivariable-adjusted differences in CPET metrics between cases and controls confirmed the associations observed.

CONCLUSION

We described known and novel associations of CRF components with demographics, anthropometrics, cardiometabolic and pulmonary diseases and medication intake in a large patient sample. The clinical implications of long-term noncardiovascular drug intake for CPET results require further investigation.

Respiratory gas kinetics in patients with congestive heart failure during recovery from peak exercise

BACKGROUND

Cardiopulmonary Exercise Testing (CPX) is essential for the assessment of exercise capacity for patients with Chronic Heart Failure (CHF). Respiratory gas and hemodynamic parameters such as Ventilatory Efficiency (VE/VCO₂ slope), peak oxygen uptake (peak VO₂), and heart rate recovery are established diagnostic and prognostic markers for clinical populations. Previous studies have suggested the clinical value of metrics related to respiratory gas collected during recovery from peak exercise, particularly recovery time to 50% (T1/2) of peak VO₂. The current study explores these metrics in detail during recovery from peak exercise in CHF.

METHODS

Patients with CHF who were referred for CPX and healthy individuals without formal diagnoses were assessed for inclusion. All subjects performed CPX on cycle ergometers to volitional exhaustion and were monitored for at least five minutes of recovery. CPX data were analyzed for overshoot of respiratory exchange ratio (RER=VCO₂/VO₂), ventilatory equivalent for oxygen (VE/VO₂), end-tidal partial pressure of oxygen (PETO₂), and T1/2 of peak VO₂ and VCO₂.

RESULTS

Thirty-two patients with CHF and 30 controls were included. Peak VO₂ differed significantly between patients and controls (13.5 ± 3.8 vs. 32.5 ± 9.8 mL/Kg*min^-1, p < 0.001). Mean Left Ventricular Ejection Fraction (LVEF) was 35.9 ± 9.8% for patients with CHF compared to 61.1 ± 8.2% in the control group. The T1/2 of VO₂, VCO₂ and VE was significantly higher in patients (111.3 ± 51.0, 132.0 ± 38.8 and 155.6 ± 45.5s) than in controls (58.08 ± 13.2, 74.3 ± 21.1, 96.7 ± 36.8s; p < 0.001) while the overshoot of PETO₂, VE/VO₂ and RER was significantly lower in patients (7.2 ± 3.3, 41.9 ± 29.1 and 25.0 ± 13.6%) than in controls (10.1 ± 4.6, 62.1 ± 17.7 and 38.7 ± 15.1%; all p < 0.01). Most of the recovery metrics were significantly correlated with peak VO₂ in CHF patients, but not with LVEF.

CONCLUSIONS

Patients with CHF have a significantly blunted recovery from peak exercise. This is reflected in delays of VO₂, VCO₂, VE, PETO₂, RER and VE/VO₂, reflecting a greater energy required to return to baseline. Abnormal respiratory gas kinetics in CHF was negatively correlated with peak VO₂ but not baseline LVEF.

Prognostic value of peak work rate indexed by left ventricular diameter

Left ventricular diameter (LVEDD) increases with systematic endurance training but also in various cardiac diseases. High exercise capacity associates with favorable outcomes. We hypothesized that peak work rate (W_peak) indexed to LVEDD would carry prognostic information and aimed to evaluate the association between W_peak/LVEDD_rest and cardiovascular mortality. W_peak/LVEDD_rest (W/mm) was calculated in patients with an echocardiographic examination within 3 months of a maximal cycle ergometer exercise test. Low W_peak/LVEDD_rest was defined as a value below the sex- and age-specific 5th percentile among lower-risk subjects. The association with cardiovascular mortality was evaluated using Cox regression. In total, 3083 patients were included (8.0 [5.4-11.1] years of follow-up, 249 (8%) cardiovascular deaths). W_peak/LVEDD_rest (W/mm) was associated with cardiovascular mortality (adjusted hazard ratio (HR) 0.28 [0.22-0.36]), similar to W_peak in % of predicted, with identical prognostic strength when adjusted for age and sex (C-statistics 0.87 for both). A combination of low W_peak/LVEDD_rest and low W_peak was associated with a particularly poor prognosis (adjusted HR 6.4 [4.0-10.3]). W_peak/LVEDD_rest was associated with cardiovascular mortality but did not provide incremental prognostic value to W_peak alone. The combination of a low W_peak/LVEDD_rest and low W_peak was associated with a particularly poor prognosis.

Enhancing students' understanding of cardiac physiology by using 4D visualization

Difficulties in achieving knowledge about physiology and anatomy of the beating heart highlight the challenges with more traditional pedagogical methods. Recent research regarding anatomy education has mainly focused on digital three-dimensional models. However, these pedagogical improvements may not be entirely applicable to cardiac anatomy and physiology due to the multidimensional complexity with moving anatomy and complex blood flow. The aim of this study was therefore to evaluate whether high quality time-resolved anatomical images combined with realistic blood flow simulations improve the understanding of cardiac structures and function. Three time-resolved datasets were acquired using time-resolved computed tomography and blood flow was computed using Computational Fluid Dynamics. The anatomical and blood flow information was combined and interactively visualized using volume rendering on an advanced stereo projection system. The setup was tested in interactive lectures for medical students. Ninety-seven students participated. Summative assessment of examinations showed significantly improved mean score (18.1 ± 4.5 vs 20.3 ± 4.9, p = 0.002). This improvement was driven by knowledge regarding myocardial hypertrophy and pressure-velocity differences over a stenotic valve. Additionally, a supplementary formative assessment showed significantly more agreeing answers than disagreeing answers (p < 0.001) when the participants subjectively evaluated the contribution of the visualizations to their education and knowledge. In conclusion, the use of simultaneous visualization of time-resolved anatomy data and simulated blood flow improved medical students' results, with a particular effect on understanding of cardiac physiology and these simulations may be useful educational tools for teaching complex anatomical and physiological concepts.

Reference equations for breathlessness during incremental cycle exercise testing

Background

Exertional breathlessness is commonly assessed using incremental exercise testing (IET), but reference equations for breathlessness responses are lacking. We aimed to develop reference equations for breathlessness intensity during IET.

Methods

Retrospective, consecutive cohort study of adults undergoing IET in Sweden. Exclusion criteria included cardiac or respiratory disease, death or any of the aforementioned diagnoses within 1 year of the IET, morbid obesity, abnormally low exercise capacity, submaximal exertion, or an abnormal exercise test. Probabilities for breathlessness intensity ratings (Borg CR10) during IET in relation to power output (%predWmax), age, sex, height, and body mass were analysed using marginal ordinal logistic regression. Reference equations for males and females were derived to predict the upper limit of normal (ULN), and the probability of different Borg CR10 intensity ratings.

Results

2581 participants (43% female) aged 18–90 years were included. Mean breathlessness intensity was similar between sexes at peak exertion (6.7±1.5versus6.4±1.5 Borg CR10 units) and throughout exercise in relation to %predWmax. Final reference equations included age, height and %predWmaxfor males, whereas height was not included for females. The models showed a close fit to observed breathlessness intensity ratings across %predWmaxvalues. Models using absolute W did not show superior fit. Scripts are provided for calculating the probability for different breathlessness intensity ratings, and the ULN by %predWmaxthroughout IET.

Conclusion

We present the first reference equations for interpreting breathlessness intensity during incremental cycle exercise testing in males and females aged 18–90 years.

Defining left ventricular remodeling using lean body mass allometry: a UK Biobank study

PURPOSE

The geometric patterns of ventricular remodeling are determined using indexed left ventricular mass (LVM), end-diastolic volume (LVEDV) and concentricity, most often measured using the mass-to-volume ratio (MVR). The aims of this study were to validate lean body mass (LBM)-based allometric coefficients for scaling and to determine an index of concentricity that is independent of both volume and LBM.

METHODS

Participants from the UK Biobank who underwent both CMR and dual-energy X-ray absorptiometry (DXA) during 2014-2015 were considered (n = 5064). We excluded participants aged ≥ 70 years or those with cardiometabolic risk factors. We determined allometric coefficients for scaling using linear regression of the logarithmically transformed ventricular remodeling parameters. We further defined a multiplicative allometric relationship for LV concentricity (LVC) adjusting for both LVEDV and LBM.

RESULTS

A total of 1638 individuals (1057 female) were included. In subjects with lower body fat percentage (< 25% in males, < 35% in females, n = 644), the LBM allometric coefficients for scaling LVM and LVEDV were 0.85 ± 0.06 and 0.85 ± 0.03 respectively (R² = 0.61 and 0.57, P < 0.001), with no evidence of sex-allometry interaction. While the MVR was independent of LBM, it demonstrated a negative association with LVEDV in (females: r = - 0.44, P < 0.001; males: - 0.38, P < 0.001). In contrast, LVC was independent of both LVEDV and LBM [LVC = LVM/(LVEDV^0.40 × LBM^0.50)] leading to increased overlap between LV hypertrophy and higher concentricity.

CONCLUSIONS

We validated allometric coefficients for LBM-based scaling for CMR indexed parameters relevant for classifying geometric patterns of ventricular remodeling.

Post systolic shortening by speckle tracking echocardiography as a predictor for cardiovascular events in patients with type 2 diabetes

Background

Post systolic shortening (PSS), measured by speckle tracking echocardiography has emerged as a novel method to evaluate left ventricular function and has been linked to adverse outcomes.

Purpose

Our aim was to assess if the presence of pathological PSS had prognostic value in the prediction of major cardiovascular events in a cohort of patients with type-II diabetes (T2D).

Method

Three-hundred-and-sixty-four patients with T2D in the CARDIPP study (Cardiovascular Risk factors in Patients with Diabetes – a Prospective study in Primary care) underwent echocardiography between 2005 and 2009. All patients were evaluated with strain analysis by speckle tracking. PSS was defined as any myocardial contraction occurring after aortic valve closure (Figure 1). Pathological PSS was defined as a post systolic index (PSI) &gt;5% where PSI was calculated as: (peak global longitudinal strain – peak systolic longitudinal strain) / (peak global longitudinal strain) x 100. The composite endpoint of any major cardiovascular event (MACE) was defined as the diagnosis of or death in heart failure, myocardial infarction, or stroke. Cox proportional hazard ratios (HR) with 95% confidence intervals were calculated and were adjusted for sex, age, body mass index, hypertension, smoking, previous cardiovascular events and HbA1c.

Results

Mean follow-up time was 11.2±2.3 years. Patients with pathological PSS had an increased unadjusted risk of MACE, (HR 3.73, 95% CI 2.06–6.76), which persisted after adjustment (HR 2.20, 95% CI 1.11–4.37) as compared to subjects without pathological PSS. When adding PSS to a risk prediction model including Global Longitudinal Strain (GLS), the adjusted HR (95% CI) for MACE was 2.94 (1.33–6.52) for subjects with reduced GLS (lower limit of normal −16%) and PSI &gt;5%, compared to those with normal GLS and PSI ≤5%. Adverse events were more common in subjects with the combination of pathological PSS and GLS (Figure 2).

Conclusions

Our results suggest that PSS may provide important additional prognostic information in patients with T2D.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): This work was funded by grant support from FORSS, the Research Council of Southeastern Sweden and from FUTURUM, the Research Council of Jönköping.

Ventilatory efficiency in combination with peak oxygen uptake improves risk stratification in patients undergoing lobectomy

Objective

We aimed to evaluate whether or not using the slope of the increase in minute ventilation in relation to carbon dioxide (VE/VCo₂-slope), with a cutoff value of 35, could improve risk stratification for major pulmonary complications or death following lobectomy in lung cancer patients at moderate risk (Vo_2peak = 10-20 mL/kg/min).

Methods

Single center, retrospective analysis of 146 patients with lung cancer who underwent lobectomy and preoperative cardiopulmonary exercise testing in 2008-2020. The main outcome was any major pulmonary complication or death within 30 days of surgery. Patients were categorized based on their preoperative cardiopulmonary exercise testing as: low-risk group, peak oxygen uptake >20 mL/kg/min; low-moderate risk, peak oxygen uptake 10 to 20 mL/kg/min and VE/VCo₂-slope <35; and moderate-high risk, peak oxygen uptake 10 to 20 mL/kg/min and VE/VCo₂-slope ≥35. The frequency of complications between groups was compared using χ² test. Logistic regression was used to calculate the odds ratio with 95% CI for the main outcome based on the cardiopulmonary exercise testing group.

Results

Overall, 25 patients (17%) experienced a major pulmonary complication or died (2 deaths). The frequency of complications differed between the cardiopulmonary exercise testing groups: 29%, 13%, and 8% in the moderate-high, low-moderate, and low-risk group, respectively (P = .023). Using the low-risk group as reference, the adjusted odds ratio for the low-moderate risk group was 3.44 (95% CI, 0.66-17.90), whereas the odds ratio for the moderate-high risk group was 8.87 (95% CI, 1.86-42.39).

Conclusions

Using the VE/VCo₂-slope with a cutoff value of 35 improved risk stratification for major pulmonary complications following lobectomy in lung cancer patients with moderate risk based on a peak oxygen uptake of 10 to 20 mL/kg/min. This suggests that the VE/VCo₂-slope can be used for preoperative risk evaluation in lung cancer lobectomy.

The Identification and Management of High Blood Pressure Using Exercise Blood Pressure: Current Evidence and Practical Guidance

High blood pressure (BP) is a leading risk factor for cardiovascular disease (CVD). The identification of high BP is conventionally based on in-clinic (resting) BP measures, performed within primary health care settings. However, many cases of high BP go unrecognised or remain inadequately controlled. Thus, there is a need for complementary settings and methods for BP assessment to identify and control high BP more effectively. Exaggerated exercise BP is associated with increased CVD risk and may be a medium to improve identification and control of high BP because it is suggestive of high BP gone undetected on the basis of standard in-clinic BP measures at rest. This paper provides the evidence to support a pathway to aid identification and control of high BP in clinical exercise settings via the measurement of exercise BP. It is recommended that exercise professionals conducting exercise testing should measure BP at a fixed submaximal exercise workload at moderate intensity (e.g., ~70% age-predicted heart rate maximum, stage 1-2 of a standard Bruce treadmill protocol). If exercise systolic BP is raised (≥170 mmHg), uncontrolled high BP should be assumed and should trigger correspondence with a primary care physician to encourage follow-up care to ascertain true BP control (i.e., home, or ambulatory BP) alongside a hypertension-guided exercise and lifestyle intervention to lower CVD risk related to high BP.

Classification and occurrence of an abnormal breathing pattern during cardiopulmonary exercise testing in subjects with persistent symptoms following COVID-19 disease

Reduced exercise capacity and several limiting symptoms during exercise have been reported following severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. From clinical observations, we hypothesized that an abnormal breathing pattern (BrP) during exercise may be common in these patients and related to reduced exercise capacity. We aimed to (a) evaluate a method to classify the BrP as normal/abnormal or borderline in terms of inter-rater agreement; (b) determine the occurrence of an abnormal BrP in patients with post-COVID; and (c) compare characteristics of post-COVID patients with normal and abnormal BrP. In a retrospective, cross-sectional study of patients referred for CPET due to post-COVID April 2020-April 2021, we selected subjects without a history of intensive care and with available medical records. Three raters independently categorized patients' BrP as normal, abnormal, or borderline, using four traditional CPET plots (respiratory exchange ratio, tidal volume over ventilation, ventilatory equivalent for oxygen, and ventilation over time). Out of 20 patients (11 male), 10 were categorized as having a normal, 7 an abnormal, and three a borderline BrP. Inter-rater agreement was good (Fleiss' kappa: 0.66 [0.66-0.67]). Subjects with an abnormal BrP had lower peak ventilation, lower exercise capacity, similar ventilatory efficiency and a similar level of dyspnea at peak exercise, as did subjects with a normal BrP. Patients' BrP was possible to classify with good agreement between observers. A third of patients had an abnormal BrP, associated with lower exercise capacity, which could possibly explain exercise related symptoms in some patients with post-COVID syndrome.

Peak exercise SBP and future risk of cardiovascular disease and mortality

OBJECTIVES

This study aimed to evaluate the risk of all-cause mortality and incident cardiovascular disease associated with peak systolic blood pressure (PeakSBP) at clinical exercise testing.

METHODS

Data from 10 096 clinical exercise tests (54% men, age 18-85 years) was cross-linked with outcome data from national registries. PeakSBP was compared with recently published reference percentiles as well as expressed as percentage predicted PeakSBP using reference equations.Natural cubic spline modelling and Cox regression were used to analyse data stratified by sex and baseline cardiovascular risk profile.

RESULTS

Median [IQR] follow-up times were 7.9 [5.7] years (all-cause mortality) and 5.6 [5.9] years (incident cardiovascular disease), respectively. The adjusted risk of all-cause mortality [hazard ratio, 95% confidence interval (95% CI)] for individuals with PeakSBP below the 10th percentile was 2.00 (1.59-2.52) in men and 2.60 (1.97-3.44) in women, compared with individuals within the 10th--90th percentile. The corresponding risk for incident cardiovascular disease was 1.55 (1.28-1.89, men) and 1.34 (1.05-1.71, women). For males in the upper 90th percentile, compared with individuals within the 10th--90th percentile, the adjusted risks of all-cause death and incident cardiovascular disease were 0.35 (0.22-0.54) and 0.72 (0.57-0.92), respectively, while not statistically significant in women. Spline modelling revealed a continuous increase in risk with PeakSBP values less than 100% of predicted in both sexes, with no increase in risk more than 100% of predicted.

CONCLUSION

Low, but not high, PeakSBP was associated with an increased risk of mortality and future cardiovascular disease. Using reference standards for PeakSBP could facilitate clinical risk stratification across patients of varying sex, age and exercise capacity.

Incremental value of diastolic stress test in identifying subclinical heart failure in patients with diabetes mellitus

AIMS

Resting echocardiography is a valuable method for detecting subclinical heart failure (HF) in patients with diabetes mellitus (DM). However, few studies have assessed the incremental value of diastolic stress for detecting subclinical HF in this population.

METHODS AND RESULTS

Asymptomatic patients with Type 2 DM were prospectively enrolled. Subclinical HF was assessed using systolic dysfunction (left ventricular longitudinal strain <16% at rest and <19% after exercise in absolute value), abnormal cardiac morphology, or diastolic dysfunction (E/e' > 10). Metabolic equivalents (METs) were calculated using treadmill speed and grade, and functional capacity was assessed by percent-predicted METs (ppMETs). Among 161 patients studied (mean age of 59 ± 11 years and 57% male sex), subclinical HF was observed in 68% at rest and in 79% with exercise. Among characteristics, diastolic stress had the highest yield in improving detection of HF with 57% of abnormal cases after exercise and 45% at rest. Patients with revealed diastolic dysfunction during stress had significantly lower exercise capacity than patients with normal diastolic stress (7.3 ± 2.1 vs. 8.8 ± 2.5, P < 0.001 for peak METs and 91 ± 30% vs. 105 ± 30%, P = 0.04 for ppMETs). On multivariable modelling found that age (beta = -0.33), male sex (beta = 0.21), body mass index (beta = -0.49), and exercise E/e' >10 (beta = -0.17) were independently associated with peak METs (combined R2 = 0.46). A network correlation map revealed the connectivity of peak METs and diastolic properties as central features in patients with DM.

CONCLUSION

Diastolic stress test improves the detection of subclinical HF in patients with diabetes mellitus.

Low but not high exercise systolic blood pressure is associated with long-term all-cause mortality

Objectives

The risks associated with achieving a high peak systolic blood pressure (SBP) during clinical exercise testing remain controversial, although this issue has not been evaluated in relation to predicted SBP standards. This cohort study aimed to evaluate the long-term risk of all-cause mortality in males in relation to reference values of peak SBP and the increase in SBP during exercise from the Fitness Registry and the Importance of Exercise: A National Database (FRIEND).

Methods

We followed 7164 males (mean age: 58.2±10.6 years) over 95 998 person-years of follow-up (mean 13.4±5.4 years), who performed a maximal treadmill exercise test at baseline. SBP was measured at rest and at peak exercise. Risk of all-cause mortality over 20 years (Cox regression) was determined in relation to reference percentiles of peak SBP and increase in SBP with exercise: <10th (low), 10th-90th, >90th (high) percentiles.

Results

A high peak or a large increase in SBP with exercise was not associated with all-cause mortality. Subjects with a low peak SBP had a 20% higher unadjusted risk for all-cause death compared with those with a normal value (1.20 (1.11-1.31)), and a statistically non-significant 7% higher risk after adjustment for all baseline risk factors (1.07 (0.97-1.18)). The corresponding unadjusted and adjusted risks associated with a low increase in SBP were 1.24 (1.15-1.35) and 1.11 (1.02-1.21), respectively.

Conclusions

A low-but not high-peak SBP is associated with increased unadjusted risk of all-cause mortality. The FRIEND percentiles of exercise SBP can aid clinicians in individualising risk assessment.

Typical angina during exercise stress testing improves the prediction of future acute coronary syndrome

INTRODUCTION

The prognostic value of angina during exercise stress testing is controversial, possibly due to previous studies not differentiating typical from non-typical angina. We aimed to assess the prognostic value of typical angina alone, or in combination with ST depression, during exercise stress testing for predicting cardiovascular events.

METHODS

We conducted a prospective observational cohort study including all patients who performed a clinical exercise stress test at the department of Clinical Physiology, Kalmar County Hospital between 2005 and 2012. The association between typical angina/ST depression and incident acute coronary syndrome (ACS) and cardiovascular mortality were analysed using Cox regression for long-term and 1-year follow-up.

RESULTS

Out of 11605 patients (median follow-up 6.7 years), 623 (5.4%) developed ACS and 319 (2.7%) died from cardiovascular causes. Compared to patients with no angina and no ST depression, typical angina and ST depression were associated with increased risk of future ACS; hazard ratio (HR) 3.5 ([95%CI] 2.6-4.7). This association was even stronger for ACS within one year (typical angina with and without concomitant ST depression; HR 20.8 (13.9-31.3) and 9.7 (6.1-15.4), respectively). Concordance statistics for ST depression in predicting ACS during long-term follow-up was 0.58 (0.56-0.60) and 0.69 (0.65-0.73) for ACS within one year, and 0.64 (0.62-0.66) and 0.77 (0.73-0.81), respectively, when typical angina was added to the model.

CONCLUSIONS

Typical angina during exercise stress testing is predictive of future ACS, especially in combination with ST depression, and during the first year after the test.

Donor and Recipient Size Matching in Heart Transplantation With Predicted Heart and Lean Body Mass

Donor and recipient size matching during heart transplant can be assessed using weight or predicted heart mass (PHM) ratios. We developed sex-specific allomteric equations for PHM and predicted lean body mass (PLBM) using the United Kingdom Biobank (UKB) and evaluated their predictive value in the United Network of Organ Sharing database. Donor and recipient size matching was based on weight, PHM and PLBM ratios. PHM was calculated using the Multiethnic Study of Atherosclerosis and UKB equations. PLBM was calculated using the UKB and National Health and Nutrition Examination Survey equations. Relative prognostic utility was compared using multivariable Cox analysis, adjusted for predictors of 1-year survival in the Scientific Registry of Transplant Recipients model. Of 53,648 adult patients in the United Network of Organ Sharing database between 1996 and 2016, 6528 (12.2%) died within the first year. In multivariable analysis, undersized matches by any metric were associated with increased 1-year mortality (all P < 0.01). Oversized matches were at increased risk using PHM or PLBM (all P < 0.01), but not weight ratio. There were significant differences in classification of size matching by weight or PHM in sex-mismatched donor-recipient pairs. A significant interaction was observed between pulmonary hypertension and donor undersizing (hazard ratio 1.15, P = 0.026) suggesting increased risk of undersizing in pulmonary hypertension. Donor and recipient size matching with simplified PHM and PLBM offered an advantage over total body weight and may be more important for sex-mismatched donor-recipient pairs. Donor undersizing is associated with worse outcomes in patients with pulmonary hypertension.

Quantifying the Influence of Wedge Pressure, Age, and Heart Rate on the Systolic Thresholds for Detection of Pulmonary Hypertension

Background The strong linear relation between mean (MPAP) and systolic (SPAP) pulmonary arterial pressure (eg, SPAP=1.62×MPAP) has been mainly reported in precapillary pulmonary hypertension. This study sought to quantify the influence of pulmonary arterial wedge pressure (PAWP), heart rate, and age on the MPAP-SPAP relation. Methods and Results An allometric equation relating invasive MPAP and SPAP was developed in 1135 patients with pulmonary arterial hypertension, advanced lung disease, chronic thromboembolic pulmonary hypertension, or left heart failure. The equation was validated in 60 885 patients from the United Network for Organ Sharing (UNOS) database referred for heart and/or lung transplant. The MPAP/SPAP longitudinal stability was assessed in pulmonary arterial hypertension with repeated right heart catheterization. The equation obtained was SPAP=1.39×MPAP×PAWP^-0.07×(60/heart rate)^0.12×age^0.08 (P<0.001). It was validated in the UNOS cohort (R²=0.93, P<0.001), regardless of the type of organ(s) patients were listed for (mean bias [-1.96 SD; 1.96 SD] was 0.94 [-8.00; 9.88] for heart, 1.34 [-7.81; 10.49] for lung and 0.25 [-16.74; 17.24] mm Hg for heart-lung recipients). Thresholds of SPAP for MPAP=25 and 20 mm Hg were lower in patients with higher PAWP (37.2 and 29.8 mm Hg) than in those with pulmonary arterial hypertension (40.1 and 32.0 mm Hg). In 186 patients with pulmonary arterial hypertension, the predicted MPAP/SPAP was stable over time (0.63±0.03 at baseline and follow-up catheterization, P=0.43). Conclusions This study quantifies the impact of PAWP, and to a lesser extent heart rate and age, on the MPAP-SPAP relation, supporting lower SPAP thresholds for pulmonary hypertension diagnosis in patients with higher PAWP for echocardiography-based epidemiological studies.

Impact of the distance from the chest wall to the heart on surface ECG voltage in athletes

Objective

Available ECG criteria for detection of left ventricular (LV) hypertrophy have been reported to have limited diagnostic capability. Our goal was to describe how the distance between the chest wall and the left ventricle determined by echocardiography affected the relationship between ECG voltage and LV mass (LVM) in athletes.

Methods

We retrospectively evaluated digitised ECG data from college athletes undergoing routine echocardiography as part of their preparticipation evaluation. Along with LV mass and volume, we determined the chest wall–LV distance in the parasternal short-axis and long-axis views from two-dimensional transthoracic echocardiographic images and explored the relation with ECG QRS voltages in all leads, as well as summed voltages as included in six major ECG-LVH criteria.

Results

239 athletes (43 women) were included (age 19±1 years). In men, greater LV–chest wall distance was associated with higher R-wave amplitudes in leads aVL and I (R=0.20 and R=0.25, both p<0.01), while in women greater distance was associated with higher R-amplitudes in V5 and V6 (R=0.42 and R=0.34, both p<0.01). In women, the chest wall–LV distance was the only variable independently (and positively) associated with R V5 voltage, while LVM, height and weight contributed to the relationship in men.

Conclusions

The chest wall–LV distance was weakly associated with ECG voltage in athletes. Inconsistent associations in men and women imply different intrathoracic factors affecting impedance and conductance between sexes. This may help explain the poor relationship between QRS voltage and LVM in athletes.

Age- and gender-specific upper limits and reference equations for workload-indexed systolic blood pressure response during bicycle ergometry

BACKGROUND

Guidelines recommend considering workload in interpretation of the systolic blood pressure (SBP) response to exercise, but reference values are lacking.

DESIGN

This was a retrospective, consecutive cohort study.

METHODS

From 12,976 subjects aged 18-85 years who performed a bicycle ergometer exercise test at one centre in Sweden during the years 2005-2016, we excluded those with prevalent cardiovascular disease, comorbidities, cardiac risk factors or medications. We extracted SBP, heart rate and workload (watt) from ≥ 3 time points from each test. The SBP/watt-slope and the SBP/watt-ratio at peak exercise were calculated. Age- and sex-specific mean values, standard deviations and 90th and 95th percentiles were determined. Reference equations for workload-indexed and peak SBP were derived using multiple linear regression analysis, including sex, age, workload, SBP at rest and anthropometric variables as predictors.

RESULTS

A final sample of 3839 healthy subjects (n = 1620 female) were included. While females had lower mean peak SBP than males (188 ± 24 vs 202 ± 22 mmHg, p < 0.001), workload-indexed SBP measures were markedly higher in females; SBP/watt-slope: 0.52 ± 0.21 versus 0.41 ± 0.15 mmHg/watt (p < 0.001); peak SBP/watt-ratio: 1.35 ± 0.34 versus 0.90 ± 0.21 mmHg/watt (p < 0.001). Age, sex, exercise capacity, resting SBP and height were significant predictors of the workload-indexed SBP parameters and were included in the reference equations.

CONCLUSIONS

These novel reference values can aid clinicians and exercise physiologists in interpreting the SBP response to exercise and may provide a basis for future research on the prognostic impact of exercise SBP. In females, a markedly higher SBP in relation to workload could imply a greater peripheral vascular resistance during exercise than in males.

Limitations of Electrocardiography for Detecting Left Ventricular Hypertrophy or Concentric Remodeling in Athletes

BACKGROUND

Electrocardiography (ECG) is used to screen for left ventricular hypertrophy (LVH), but common ECG-LVH criteria have been found less effective in athletes. The purpose of this study was to comprehensively evaluate the value of ECG for identifying athletes with LVH or a concentric cardiac phenotype.

METHODS

A retrospective analysis of 196 male Division I college athletes routinely screened with ECG and echocardiography within the Stanford Athletic Cardiovascular Screening Program was performed. Left-ventricular mass and volume were determined using echocardiography. LVH was defined as left ventricular mass (LVM) >102 g/m²; a concentric cardiac phenotype as LVM-to-volume (M/V) ≥1.05 g/mL. Twelve-lead electrocardiograms including high-resolution time intervals and QRS voltages were obtained. Thirty-seven previously published ECG-LVH criteria were applied, of which the majority have never been evaluated in athletes. C-statistics, including area under the receiver operating curve (AUC) and likelihood ratios were calculated.

RESULTS

ECG lead voltages were poorly associated with LVM (r = 0.18-0.30) and M/V (r = 0.15-0.25). The proportion of athletes with ECG-LVH was 0%-74% across criteria, with sensitivity and specificity ranging between 0% and 91% and 27% and 99.5%, respectively. The average AUC of the criteria in identifying the 11 athletes with LVH was 0.57 (95% confidence interval [CI] 0.56-0.59), and the average AUC for identifying the 8 athletes with a concentric phenotype was 0.59 (95% CI 0.56-0.62).

CONCLUSION

The diagnostic capacity of all ECG-LVH criteria were inadequate and, therefore, not clinically useful in screening for LVH or a concentric phenotype in athletes. This is probably due to the weak association between LVM and ECG voltage.

Echocardiographic Assessment of Left Ventricular Remodeling in American Style Footballers

Several athletic programs incorporate echocardiography during pre-participation screening of American Style Football (ASF) players with great variability in reported echocardiographic values. Pre-participation screening was performed in National Collegiate Athletic Association Division I ASF players from 2008 to 2016 at the Division of Sports Cardiology. The echocardiographic protocol focused on left ventricular (LV) mass, mass-to-volume ratio, sphericity, ejection fraction, and longitudinal Lagrangian strain. LV mass was calculated using the area-length method in end-diastole and end-systole. A total of two hundred and thirty players were included (18±1 years, 57% were Caucasian, body mass index 29±4 kg/m²) after four players (2%) were excluded for pathological findings. Although there was no difference in indexed LV mass by race (Caucasian 78±11 vs. African American 81±10 g/m², p=0.089) or sphericity (Caucasian 1.81±0.13 vs. African American 1.78±0.14, p=0.130), the mass-to-volume ratio was higher in African Americans (0.91±0.09 vs. 0.83±0.08, p<0.001). No race-specific differences were noted in LV longitudinal Lagrangian strain. Player position appeared to have a limited role in defining LV remodeling. In conclusion, significant echocardiographic differences were observed in mass-to-volume ratio between African American and Caucasian players. These demographics should be considered as part of pre-participation screening.

P2488The 2013 ACC/AHA pooled cohort equations and insulin resistance status for detection of early-stage heart failure in the community

Objectives

Detection of heart failure (HF) in its subclinical phase would allow timely initiation of preventive measures that counter its pathophysiology. Here, we assessed the usefulness of traditional cardiovascular (CV) risk assessment and insulin resistance status to detect early-stage HF.

Methods

In 984 participants (mean age, 57.0 years, 52.3% women), we derived echocardiographic indexes of left ventricular (LV) structure and function and calculated the 10-year risk for a first atherosclerotic CV disease (ASCVD) using the 2013 ACC/AHA risk score. We assessed the discriminatory value of this risk score to detect LV maladaptation and the improvements in reclassification by insulin resistance status (HOMA-IR).

Results

The probability for LV maladaptation rose progressively with the 10-year ASCVD risk increasing. Participants at high 10-year ASCVD risk (>7.5%) had indeed significantly higher odds for LV concentric remodeling (odds ratio, 4.84), LV hypertrophy (OR, 5.93), abnormal LV longitudinal strain (OR, 2.04) and LV diastolic dysfunction (OR, 25.3) as compared to those at low ASCVD risk (<2.5%; P≤0.0003). Adding markers of insulin resistance to the ACC/AHA risk score moderately improved the integrated discrimination and net reclassification of all LV maladaptive phenotypes (P≤0.022) except LV diastolic dysfunction (P≥0.059). LV remodeling and abnormal LS was particularly more likely in insulin-resistant participants with a 10-year ASCVD risk between 5% and 15% than in their insulin-sensitive counterparts.

Prediction of early-stage HF profiles 2013 ACC/AHA risk score Addition of insulin resistance status to the 2013 ACC/AHA risk score AUC (95% CI) Integrated Discrimination Improvement Net Reclassification Improvement Absolute IDI (%) P value NRI (95% CI) P value LV concentric remodeling 0.70 (0.66 to 0.74) 0.0083 (11.3%) 0.022 0.23 (0.067 to 0.39) 0.0058 LV hypertrophy 0.70 (0.66 to 0.74) 0.017 (20.7%) 0.0033 0.27 (0.11 to 0.43) 0.0011 Abnormal LV LS 0.56 (0.53 to 0.62) 0.022 (202.0%) <0.0001 0.33 (0.18 to 0.49) <0.0001 LV diastolic dysfunction 0.82 (0.78 to 0.86) 0.0007 (0.45%) 0.84 0.093 (−0.11 to 0.30) 0.38 ≥2 LV abnormalities 0.76 (0.72 to 0.80) 0.0087 (7.3%) 0.071 0.22 (0.042 to 0.40) 0.016 The integrated discrimination improvement (IDI) and net reclassification improvement (NRI) reflect the improvements in classification by adding insulin resistance (by HOMA-IR) to the 2013 ACC/AHA risk score. HOMA-IR, Homeostatic Model for Assessment of Insulin Resistance; LS, longitudinal strain; LV, left ventricular.

Risk enhancers of LV maladaptation

Conclusions

The 2013 ACC/AHA risk score adequately captured the risk for echocardiographic phenotypes of early-stage HF. As risk enhancer, insulin resistance might improve risk stratification of subclinical HF in subjects at intermediate risk.

Acknowledgement/Funding

The European Union, European Research Council and the Flanders Scientific Research Fund supported this study.

P5471Baseline characteristics, healthcare resource use and clinical outcomes of stable post-myocardial infarction patients with diabetes: insights from the global prospective TIGRIS study

Background

There is a growing prevalence of diabetes worldwide in patients in the general population, including those with prior myocardial infarction (MI).

Purpose

To describe the characteristics, health status, resource utilization and clinical adverse events of stable post-MI patients with diabetes.

Methods

The long-Term rIsk, clinical manaGement and healthcare Resource utilization of stable coronary artery dISease (TIGRIS) prospective observational study (NCT01866904) obtained data from 8985 stable patients 1–3 years post-MI from 369 centres in 25 countries, who provided diabetes status (no, yes, insulin-treated) and follow-up. Diabetes status, other patient characteristics, medications, medical history and healthcare resource utilization were recorded at enrolment. Health status was assessed at enrolment, 1 and 2 years by EQ-5D-3L and converted to an EQ-5D score. Deaths, cardiovascular (CV) events, bleeding events and related hospitalizations were recorded during 2 years of follow-up.

Results

Diabetes mellitus (DM) was prevalent at enrolment in 2966 (33%) patients of whom 872 (29%) were insulin-treated. Compared to patients without DM, those with DM had a higher mean body mass index (28.2 vs 26.6kg/m2) and heart rate (71 vs 67bpm), were more likely to have had ≥2 prior MIs (12% vs 10%), chronic kidney disease (10% vs 6%), peripheral artery disease (10% vs 5%), heart failure (15% vs 10%), anaemia (4% vs 2%), angina (12% vs 9%), stroke (6% vs 4%) and chronic obstructive pulmonary disease (9% vs 7%). Patients with DM reported more problems for each domain of the EQ-5D (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression), which resulted in a lower mean EQ-5D utility score at enrolment (0.83±0.22 for no-diabetes vs 0.86±0.19 for diabetes). Moreover, they also had higher CV hospitalization rates in the 6 months prior to enrolment (6.4% vs 5%). All these measures were more marked in insulin-dependent diabetics. The incidences of all-cause death, CV death and the composite of CV death, MI and stroke were all significantly higher in patients with DM, especially those on insulin (see Figure). For CV death, MI and stroke the 2-year risk ratios, compared to patients without DM, were 2.64 (P<0.001) and 1.48 (P<0.001) respectively for those with insulin-treated DM and non-insulin treated.

Figure 1

Conclusions

Within a global population of stable post-MI patients, those with DM (especially those on insulin) have poorer health status and EQ-5D utility score, higher hospitalization rates and worse clinical outcomes compared with those without DM. Thus, in cardiac clinics worldwide, patients with DM require particularly close attention.

Acknowledgement/Funding

The study was funded by AstraZeneca

P4419The association between ECG voltage and left-ventricular mass, sex, body size and the distance between the heart and chest wall in college athletes

Background

The ECG is widely used in pre-participation evaluation (PPE) of athletes (ATH). While it is assumed that greater than normal QRS voltages reflect physiologically increased left ventricular mass (LVM), this has not been adequately demonstrated in ATH.

Purpose

To examine the relation between QRS voltage on surface ECG and LVM and explore if the distance from the chest wall to mid-LV (CWLVdis) affects QRS voltage in ATH.

Methods

We examined digitized ECG data and echocardiograms in college ATH, obtained as part of routine PPE in years 2010–16. ECG parameters included R and S-wave voltage components of the Sokolow-Lyon (S-L) and Cornell criteria for LV hypertrophy (i.e. SV1 + RV5-V6 and RaVL + SV3, respectively). Transthoracic 2D echocardiography was used to determine LVM (area-length method) and the CWLVdis (detailed in Fig1A). S-L positive (SV1 + RV5-V6 >35 mV or RaVL >11 mV) ATH were compared to S-L negative by t-test, and univariate correlation and multivariable regression analysis was used to explore independent effects of body characteristics, sex, LVM and CWLVdis on QRS voltage.

Results

Included were 227 ATH (age 18.6±0.7 yr; 85% male; 60%/33% Caucasian/Afro-american). Of these, 66% played American football, 18% volleyball and 16% basketball.

Overall, mean LVM was 174±37 g (range 96–284 g), and BSA-indexed LVM was 78±12 g/m2 (range 49–108 g/m2). Mean CWLVdis was 8.5±1.1 cm (range 5.6–11.3 cm) and was greater in males (p<0.001, Fig1B).

Forty-six ATH (24%, all male) were S-L positive and no ATH were positive according to Cornell criteria. S-L positive ATH had lower BMI (25.3±3.5 vs 26.9±4.9, p=0.012), greater absolute LVM (189.1±31.3 vs. 170.1±37.4 g, p=0.002) and greater BSA-indexed LVM (85.3±10.3 vs. 76.6±11.7 g/m2, p<0.001) than S-L negative ATH. The CWLVdis was similar between S-L positive and negative ATH (8.4±1.2 vs. 8.6±1.1, respectively, p=0.213).

CWLVdis was more strongly correlated to body mass (r=0.73, p<0.001, Fig. 1C) than to height (r=0.34, p<0.001). LVM correlated weakly to ECG voltage as combined in the S-L or Cornell criteria (Fig. 1C). CWLVdis was weakly correlated with R in aVL, V5 and V6 (r=0.21, 0.16 and 0.16, all p<0.02).

In multivariate analysis, male sex (β=0.31), LVM (β=0.45) and body mass index (β=-0.37) were independently associated with the S-L summed voltage (R2 0.26, p<0.001). For Cornell summed voltage, only sex was an independent predictor (β=0.48, R2 0.22, p<001).

Figure 1

Conclusion

The R and S wave ECG amplitudes used in the two most common ECG criteria for LV hypertrophy were weakly related in the highest to lowest order to sex, LVM, body size and the distance from the LV to the chest wall in our college ATH.

6075Workload adjusted blood pressure response rather than peak systolic blood pressure is associated with increased all-cause mortality in males; results from 7097 treadmill exercise tests

Background

Systolic blood pressure (SBP) is routinely measured during exercise testing (ET) and is in part determined by cardiac output and peripheral vascular resistance. A frequently used threshold for defining hypertensive response to exercise is ≥210 mmHg but this does not account for the fact that SBP is related to workload, via cardiac output.

Purpose

To examine the prognostic implications of considering external workload (METs) adjusted SBP response to exercise.

Methods

We reviewed all symptom-limited treadmill ET in males between 1987 and 2007 at a single centre (inclusion/exclusion criteria detailed in figure 1A). SBP was measured standing at rest and at peak exercise. Workload adjusted BP response with exercise (SBP/MET slope) was calculated as ΔSBP/ΔMET. METs were calculated from peak speed and grade according to the standard American College of Sports Medicine (ACSM) formula. Age-predicted peak METs was calculated as: 18 - 0.15 × age. Ten-year Cox proportional hazard ratios (HR) with 95% confidence intervals were calculated and adjusted as outlined in figure 1B.

Results

7097 subjects were included, of which 1559 (22%) died within 10 years. Survivors were younger (57.2±10.6 y vs. 64.5±10.3 y, p<0.001) and reached higher % of age-predicted METs (97±33% vs. 82±33%, p<0.001). Survivors had higher peak SBP (181±26 vs. 176±27 mmHg, p<0.001) as well as greater ΔSBP (49±22 vs. 42±22 mmHg, p<0.001), while they had lower SBP/MET slope (7.0±4.4 vs. 8.9±6.5 mmHg/MET, p<0.001). A peak SBP ≥210 mmHg was associated with better survival; 10-yr adjusted HR: 0.76 (0.64–0.88, p<0.001). In contrast, a higher SBP/MET slope was associated with increased mortality (table 1).

Table 1. Ten year adjusted hazard ratios Variable HR (95% CI) P Variable HR (95% CI) P Variable HR (95% CI) P Peak SBP, Q1: 100–159 mmHg REF REF Delta SBP, Q1: 1–29 mmHg REF REF SBP/MET slope, Q1: 0.2–4.2 REF REF Peak SBP, Q2: 160–179 mmHg 0.81 (0.71–0.94) 0.006 Delta SBP, Q2: 30–46 mmHg 0.80 (0.70–0.91) 0.001 SBP/MET slope, Q2: 4.3–6.2 0.95 (0.81–1.12) 0.562 Peak SBP, Q3: 180–199 mmHg 0.68 (0.58–0.78) <0.001 Delta SBP, Q3: 47–61 mmHg 0.76 (0.66–0.88) <0.001 SBP/MET slope, Q3: 6.2–9.1 1.18 (1.01–1.37) 0.032 Peak SBP, Q4: ≥200 mmHg 0.60 (0.51–0.69) <0.001 Delta SBP, Q4: ≥62 mmHg 0.59 (0.50–0.69) <0.001 SBP/MET slope, Q4: ≥9.1 1.40 (1.22– 1.62) <0.001 HR, hazard ratio (adjusted according to figure 1B); SBP, systolic blood pressure; MET, metabolic equivalent of task; Q1–Q4, quartiles (Q1 as reference).

Figure 1

Conclusion

Workload adjusted blood pressure response to exercise in contrast to peak BP response was associated with increased mortality in male patients referred for ET. Of note, reaching a BP of at least 210 mmHg (suggested to define a hypertensive response to exercise) was associated with a 24% reduction in all-cause mortality.

Acknowledgement/Funding

K Hedman was supported by post-doc. grants from the Fulbright Commission, the Swedish Society of Medicine, County Council of Östergötland, Sweden

Workload-indexed blood pressure response is superior to peak systolic blood pressure in predicting all-cause mortality

AIMS

The association between peak systolic blood pressure (SBP) during exercise testing and outcome remains controversial, possibly due to the confounding effect of external workload (metabolic equivalents of task (METs)) on peak SBP as well as on survival. Indexing the increase in SBP to the increase in workload (SBP/MET-slope) could provide a more clinically relevant measure of the SBP response to exercise. We aimed to characterize the SBP/MET-slope in a large cohort referred for clinical exercise testing and to determine its relation to all-cause mortality.

METHODS AND RESULTS

Survival status for male Veterans who underwent a maximal treadmill exercise test between the years 1987 and 2007 were retrieved in 2018. We defined a subgroup of non-smoking 10-year survivors with fewer risk factors as a lower-risk reference group. Survival analyses for all-cause mortality were performed using Kaplan-Meier curves and Cox proportional hazard ratios (HRs (95% confidence interval)) adjusted for baseline age, test year, cardiovascular risk factors, medications and comorbidities. A total of 7542 subjects were followed over 18.4 (interquartile range 16.3) years. In lower-risk subjects (n = 709), the median (95th percentile) of the SBP/MET-slope was 4.9 (10.0) mmHg/MET. Lower peak SBP (<210 mmHg) and higher SBP/MET-slope (>10 mmHg/MET) were both associated with 20% higher mortality (adjusted HRs 1.20 (1.08-1.32) and 1.20 (1.10-1.31), respectively). In subjects with high fitness, a SBP/MET-slope > 6.2 mmHg/MET was associated with a 27% higher risk of mortality (adjusted HR 1.27 (1.12-1.45)).

CONCLUSION

In contrast to peak SBP, having a higher SBP/MET-slope was associated with increased risk of mortality. This simple, novel metric can be considered in clinical exercise testing reports.

Blood pressure in athletic preparticipation evaluation and the implication for cardiac remodelling

OBJECTIVES

To explore blood pressure (BP) in athletes at preparticipation evaluation (PPE) in the context of recently updated US and European hypertension guidelines, and to determine the relationship between BP and left ventricular (LV) remodelling.

METHODS

In this retrospective study, athletes aged 13-35 years who underwent PPE facilitated by the Stanford Sports Cardiology programme were considered. Resting BP was measured in both arms; repeated once if ≥140/90 mm Hg. Athletes with abnormal ECGs or known hypertension were excluded. BP was categorised per US/European hypertension guidelines. In a separate cohort of athletes undergoing routine PPE echocardiography, we explored the relationship between BP and LV remodelling (LV mass, mass/volume ratio, sphericity index) and LV function.

RESULTS

In cohort 1 (n=2733, 65.5% male), 34.3% of athletes exceeded US hypertension thresholds. Male sex (B=3.17, p<0.001), body mass index (BMI) (B=0.80, p<0.001) and height (B=0.25, p<0.001) were the strongest independent correlates of systolic BP. In the second cohort (n=304, ages 17-26), systolic BP was an independent correlate of LV mass/volume ratio (B=0.002, p=0.001). LV longitudinal strain was similar across BP categories, while higher BP was associated with slower early diastolic relaxation.

CONCLUSION

In a large contemporary cohort of athletes, one-third presented with BP levels above the current US guidelines' thresholds for hypertension, highlighting that lowering the BP thresholds at PPE warrants careful consideration as well as efforts to standardise measurements. Higher systolic BP was associated with male sex, BMI and height and with LV remodelling and diastolic function, suggesting elevated BP in athletes during PPE may signify a clinically relevant condition.

Vascular Adaptation to Indoor Cycling Exercise in Premenopausal Women

The early vascular adaptation to indoor cycling, a popular activity at many fitness centres, is incompletely evaluated. Forty two healthy women (21-45 years) underwent measurements of arterial wall properties and geometry as well as a maximal bicycle exercise test before and after a 3 months period during which 21 of the women joined indoor cycling classes at a gym 2-3 times per week, while 21 women served as time controls. Peak work load increased by in average 16% (p<0.001) and ascending aortic diameter by 4% (p<0.01) in the exercise group, while unchanged in control group. The exercise intervention had no significant influence on the local intima-media thickness, blood pressure or the pulse pressure wave configuration while the carotid artery distensibility (p<0.05) was higher after the intervention. There was a positive correlation between change in (Δ) peak work load and Δ-diameter of tubular ascending aorta (r=0.42, p<0.01) in the exercise group. In conclusion, after only 3 months of bicycle exercise training, signs of central arterial remodelling were seen in premenopausal women, which was associated to improvement in exercise capacity.

Cardiopulmonary exercise testing for evaluation of a randomized exercise training intervention following aortic valve replacement

Aortic valve surgery is the definitive treatment for aortic stenosis (AS). No specific recommendation is available on how exercise training should be conducted and evaluated after aortic valve replacement (AVR). This study aimed to examine the effect of aerobic exercise training on exercise capacity following AVR. In addition to our primary outcome variable, peak oxygen uptake (peakVO₂ ), the effect on submaximal cardiopulmonary variables including oxygen uptake kinetics (tau), oxygen uptake efficiency slope (OUES) and ventilatory efficiency (VE/VCO₂ slope) was evaluated. Following AVR due to AS, 12 patients were randomized to either a group receiving 12 weeks of supervised aerobic exercise training (EX) or a control group (CON). Exercise capacity was assessed by a maximal cardiopulmonary exercise test (CPET). There was a significant increase in peak load (+28%, P = 0·031) and in peakVO₂ (+23%, P = 0·031) in EX, corresponding to an increase in achieved percentage of predicted peakVO₂ from 88 to 104% (P = 0·031). For submaximal variables, there were only non-statistically significant trends in improvement between CPETs in EX. In CON, there were no significant differences in any maximal or submaximal variable between CPETs. We conclude that 12 weeks of supervised aerobic exercise training induces significant adaptations in cardiopulmonary function following AVR, especially in regard to maximal variables including peakVO₂ . In addition, we provide novel data on the effect on several submaximal variables following exercise training in this group of patients.

Vascular characteristics in young women-Effect of extensive endurance training or a sedentary lifestyle

AIM

To explore whether high-level endurance training in early age has an influence on the arterial wall properties in young women.

METHODS

Forty-seven athletes (ATH) and 52 controls (CTR), all 17-25 years of age, were further divided into runners (RUN), whole-body endurance athletes (WBA), sedentary controls (SC) and normally active controls (AC). Two-dimensional ultrasound scanning of the carotid arteries was conducted to determine local common carotid artery (CCA) geometry and wall distensibility. Pulse waves were recorded with a tonometer to determine regional pulse wave velocity (PWV) and pulse pressure waveform.

RESULTS

Carotid-radial PWV was lower in WBA than in RUN (P < .05), indicating higher arterial distensibility along the arm. Mean arterial pressure was lower in ATH than in CTR and in RUN than in WBA (P < .05). Synthesized aortic augmentation index (AI@75) was lower among ATH than among CTR (-12.8 ± 1.6 vs -2.6 ± 1.2%, P < .001) and in WBA than in RUN (-16.4 ± 2.5 vs -10.7 ± 2.0%, P < .05), suggesting a diminished return of reflection waves to the aorta during systole. Carotid-femoral PWV and intima-media thickness (IMT), lumen diameter and radial distensibility of the CCA were similar in ATH and CTR.

CONCLUSION

Elastic artery distensibility and carotid artery IMT are not different in young women with extensive endurance training over several years and in those with sedentary lifestyle. On the other hand, our data suggest that long-term endurance training is associated with potentially favourable peripheral artery adaptation, especially in sports where upper body work is added. This adaptation, if persisting later in life, could contribute to lower cardiovascular risk.

Humoral response to John Cunningham virus during pregnancy in multiple sclerosis

BACKGROUND

Pregnancy induces an immunosuppressive state in the mother to ensure immunological acceptance of the foetus. Impairment of cell-mediated immune responses may render the mother susceptible to intracellular pathogens. It is not presently known whether pregnancy alters the immunosurveillance for John Cunningham virus (JCV), an opportunistic pathogen associated with natalizumab treatment for multiple sclerosis (MS).

OBJECTIVE

To evaluate whether the humoral immune response to JCV is altered during pregnancy among MS patients and healthy controls to get insight to potential pregnancy-induced alterations related to immune response to JCV during pregnancy.

METHODS

Serum anti-JCV-antibody-indices (JCV-Ab-index) were determined by a two-step second-generation enzyme-linked immunosorbent assay in 49 MS patients during and after pregnancy and in 49 healthy controls during pregnancy. For comparison, total IgG levels and antibodies against Epstein-Barr, cytomegalo and measles viruses were similarly measured.

RESULTS

The JCV-Ab-indices of MS patients were not altered during the pregnancy (1st vs. 3rd trimester, 0.62 vs. 0.77, p = 0.99). Contrary to this, in the healthy controls JCV-Ab-indices (p = 0.005), antibody levels to the other viruses, and total IgG levels (p < 0.0001) decreased significantly during pregnancy.

CONCLUSIONS

JCV-Ab levels remain unaltered during MS pregnancy, while the total IgG concentration is reduced/diluted due to increasing plasma volumes during the course of pregnancy. This may imply a biologically significant alteration in the immune response to JCV during MS pregnancy.

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Low adherence to recommended pre-participation cardiac evaluation of Swedish athletes Pre-participation cardiac evaluation of athletes is recommended by international organizations like the European Society of Cardiology and the American Heart Association, as well as by the Swedish Sports Confederation. The purpose of the evaluation is to prevent sudden cardiac death in athletes by early identification of individuals at risk. To our knowledge, no previous study has been made regarding the implementation of pre-participation cardiac evaluation of athletes in Sweden. We performed an electronical survey addressing sports clubs in one out of 21 districts in which the Swedish Sports Confederation is geographically divided. Only four out of 22 responding clubs with elite athletes preformed cardiac evaluation. Lack of knowledge about the recommendations as well as how to perform the evaluation were mentioned as reasons not to evaluate the athletes. Our results indicate the need for more information about pre-participation cardiac evaluation of athletes in Sweden.