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.

We examined the systolic blood pressure response during maximal bicycle exercise testing in individuals without hypertension or established cardiovascular disease, and found that: When applying reference values for peak systolic blood pressure during cycling exercise, accounting for age, sex, resting blood pressure and exercise capacity, exceeding the upper limit of normal was associated with twice as high relative risk of future hypertension, compared to having a peak systolic blood pressure within normal limits. A steep increase in exercise blood pressure in relation to the increase in work rate was also associated with future hypertension but did not always coincide with elevated peak systolic blood pressure.

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 (Wpeak) indexed to LVEDD would carry prognostic information and aimed to evaluate the association between Wpeak/LVEDDrest and cardiovascular mortality. Wpeak/LVEDDrest (W/mm) was calculated in patients with an echocardiographic examination within 3 months of a maximal cycle ergometer exercise test. Low Wpeak/LVEDDrest 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). Wpeak/LVEDDrest (W/mm) was associated with cardiovascular mortality (adjusted hazard ratio (HR) 0.28 [0.22-0.36]), similar to Wpeak in % of predicted, with identical prognostic strength when adjusted for age and sex (C-statistics 0.87 for both). A combination of low Wpeak/LVEDDrest and low Wpeak was associated with a particularly poor prognosis (adjusted HR 6.4 [4.0-10.3]). Wpeak/LVEDDrest was associated with cardiovascular mortality but did not provide incremental prognostic value to Wpeak alone. The combination of a low Wpeak/LVEDDrest and low Wpeak was associated with a particularly poor prognosis.

Systolic Blood Pressure Response to Exercise in Endurance Athletes in Relation to Oxygen Uptake, Work Rate and Normative Values.

Work rate has a direct impact on the systolic blood pressure (SBP) during aerobic exercise, which may be challenging in the evaluation of the SBP response in athletes reaching high work rates. We aimed to investigate the exercise SBP response in endurance athletes in relation to oxygen uptake (VO2), work rate and to recent reference equations for exercise SBP in the general population. Endurance athletes with a left-ventricular end-diastolic diameter above the reference one performed a maximal bicycle cardiopulmonary exercise test. The increase in SBP during exercise was divided by the increase in VO2 (SBP/VO2 slope) and in Watts, respectively (SBP/W slope). The maximum SBP (SBPmax) and the SBP/W slope were compared to the predicted values. In total, 27 athletes (59% men) were included; mean age, 40 ± 10 years; mean VO2max, 50 ± 5 mL/kg/min. The mean SBP/VO2 slope was 29.8 ± 10.2 mm Hg/L/min, and the mean SBP/W slope was 0.27 ± 0.08 mm Hg/W. Compared to the predicted normative values, athletes had, on average, a 12.2 ± 17.6 mm Hg higher SBPmax and a 0.12 ± 0.08 mm Hg/W less steep SBP/W slope (p < 0.01 and p < 0.001, respectively). In conclusion, the higher SBPmax values and the less steep SBP/W slope highlight the importance of considering work rate when interpreting the SBP response in endurance athletes and suggest a need for specific normative values in athletes to help clinicians distinguish physiologically high maximal blood pressure from a pathological blood pressure response.

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.

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.

[Pre-duty medical assessment in fire-fighters requires modernization - relevance of exercise ECG is questioned]. / Oklar nytta av upprepade arbets-EKG hos brandmän.

Medical assessment of Swedish smoke diving firefighters includes cardiac evaluation by maximal exercise testing with ECG recording. The exercise ECG procedure for firefighters was introduced in 1986, and remains consistent in the recently updated guidelines from 2019.  Exercise ECG is a non-invasive and easily available method for detection of chronic coronary syndromes, but due to the declining population risk in high-income countries, its ability to accurately detect disease has decreased. Thus, the clinical relevance of exercise ECG in firefighters is questioned and the pre-duty medical assessment requires modernization.

Exercise-induced ST depression in an asymptomatic population without coronary artery disease.

Objectives. Exercise electrocardiogram (ExECG) in low risk populations frequently generates false positive ST depression. We aimed to characterize factors that are associated with exercise-induced ST depression in asymptomatic men without coronary artery disease. Design. Cycle ergometer exercise tests from 509 male firefighters without imaging proof of significant coronary artery disease were analysed. Analysed test data included heart rate at rest before exercise, and workload, blood pressure, heart rate, ST depression and ST segment slope at peak exercise. ST depression of >0.1 mV was considered significant (STdep). With a mean follow-up of 6.1 ± 1.7 years, medical records were reviewed for cardiovascular diagnoses, hyperlipidemia and diabetes. Logistic regression analysis was used for risk assessment. Results. In total, 22% had STdep in ≥1 lead. Subjects with STdep were older than those with normal ExECG (p < .001). Downsloping STdep was more common in extremity leads (9%) than in precordial leads (2%). STdep was categorized according to location (precordial/extremity) and slope direction into eight categories. Larger age-adjusted heart rate increase predicted STdep in seven categories (p < .05). Age-adjusted peak heart rate correlated with STdep in five categories, predominantly where the ST slope was positive. Peak blood pressure and exercise capacity were both associated with STdep in few categories. We found no association between STdep and hypertension, hyperlipidemia or diabetes (all p > .05). Conclusions. In asymptomatic men with a physically demanding occupation and no coronary artery disease, both age and heart rate response were associated with ST depression, whereas common cardiovascular risk factors, blood pressure response and exercise capacity were not.

ST/HR variables in firefighter exercise ECG - relation to ischemic heart disease.

Exercise electrocardiography (ExECG) is regularly performed by Swedish firefighters by law. Heart rate-corrected analysis of ST segment variables (ST/HR) has shown improved prediction of ischemic heart disease (IHD) compared to ST depression alone. This has not previously been extensively studied in asymptomatic persons with a low probability of IHD. We therefore evaluated the predictive performance of ST/HR analysis in firefighter ExECG. ExECG was studied in 521 male firefighters. During 8.4 ± 2.1 years, 2.3% (n = 12) were verified with IHD by catheterization or myocardial scintigraphy (age 51.5 ± 5.5 years) and were compared with firefighters without imaging proof of IHD (44.2 ± 10.1 years). The predictive value of ST depression, ST/HR index, ST/HR slope, and area and rotation of the ST/HR loop was calculated as age-adjusted odds ratios (OR), in 10 ECG leads. Predictive accuracy was analyzed with receiver operating characteristics (ROC) analysis. ST/HR index ≤-1.6 µV/bpm and ST/HR slope ≤-2.4 µV/bpm were associated with increased IHD risk in three individual leads (all OR > 1.0, P < 0.05). ST/HR loop area lower than the fifth percentile of non-IHD subjects indicated IHD risk in V4, V5, aVF, II, and -aVR (P < 0.05). ST depression ≤-0.1 mV was associated with IHD only in V4 (OR, 9.6, CI, 2.3-40.0). ROC analysis of each of these variables yielded areas under the curve of 0.72 or lower for all variables and leads. Clockwise-rotated ST/HR loops was associated with increased risk in most leads compared to counterclockwise rotation. The limited clinical value of ExECG in low-risk populations was emphasized, but if performed, ST/HR analysis should probably be given more importance.

Låg följsamhet till rekommenderad hjärtscreening av elitidrottare - Lägesanalys i Östergötland.

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.

Loaded treadmill walking and cycle ergometry to assess work capacity: a retrospective comparison in 424 firefighters.

The fitness of firefighters is regularly evaluated using exercise tests. We aimed to compare, with respect to age and body composition, two test modalities for the assessment work capacity. A total of 424 Swedish firefighters with cycle ergometer (CE) and treadmill (TM) tests available from Jan 2004 to Dec 2010 were included. We compared results from CE (6 min at 200 W, 250 W or incremental ramp exercise) with TM (6 min at 8° inclination, 4·5 km h-1 or faster, wearing 24-kg protective equipment). Oxygen requirements were estimated by prediction equations. It was more common to pass the TM test and fail the supposedly equivalent CE test (20%), than vice versa (0·5%), P<0·001. Low age and tall stature were significant predictors of passing both CE and TM tests (P<0·05), while low body mass predicted accomplishment of TM test only (P = 0·006). Firefighters who passed the TM but failed the supposedly equivalent CE test within 12 months had significantly lower body mass, lower BMI, lower BSA and shorter stature than did those who passed both tests. Calculated oxygen uptake was higher in TM tests compared with corresponding CE tests (P<0·001). Body constitution affected approval differently depending on the test modality. A higher approval rate in TM testing suggests lower cardiorespiratory requirements compared with CE testing, even though estimated oxygen uptake was higher during TM testing. The relevance of our findings in relation to the occupational demands needs reconsidering.