Systolic Blood Pressure Response During Exercise Stress Testing: The Henry Ford ExercIse Testing (FIT) Project

Chronotropic Incompetence in Parkinson's Disease: A Possible Marker of Severe Disease Phenotype?

Autonomic dysfunction is a prevalent feature of Parkinson's disease (PD), mediated by disease involvement of the autonomic nervous system. Chronotropic incompetence (CI) refers to inadequate increase of heart rate in response to elevated metabolic demand, partly dependent on postganglionic sympathetic tone. In a retrospective study, PD patients with/without CI were identified. We show that PD with CI was associated with a higher levodopa equivalent daily dose and Hoehn and Yahr stage, 5±2 years after motor onset. Our data support a putative role of CI as a clinical marker of a more severe disease phenotype, possibly reflecting more widespread alpha-synuclein pathology.

Echocardiographic Findings in Asymptomatic Mediastinal Lymphoma Survivors Years after Treatment Termination

Patients treated due to mediastinal lymphomas are at risk of cardiovascular complications, as they receive chemotherapy, usually containing anthracyclines, often combined with thoracic radiotherapy. The aim of this prospective study was to assess early asymptomatic cardiac dysfunction using resting and dobutamine stress echocardiography (DSE) at least 3 years after the end of mediastinal lymphoma treatment. Two groups of patients were compared: those treated with chemoradiotherapy and those exclusively treated with chemotherapy. Left ventricular contractile reserve (LVCR) during DSE was assessed using changes in LV ejection fraction (LVEF), LV global longitudinal strain (LV GLS), and a novel parameter-Force, which is the ratio of the systolic blood pressure to the LV end-systolic volume. The study included 60 patients examined at a median of 89 months after the end of treatment. Resting echocardiography showed normal LVEF of 58.9 ± 9.6%, borderline LV GLS of -17.7 ± 3%, decreased mean stroke volume (SV) of 51.4 ± 17 mL, and indexed SV of 27.3 ± 8 mL/m², and the right ventricular free wall longitudinal strain (LS) was impaired in some patients but not in all. There were no significant differences between the groups, with the exception of arterial hypertension, which was more common in the chemotherapy group (32% vs. 62.5%, p = 0.04). In resting echocardiography, only LV posterior wall LS differed significantly and was impaired in patients treated with chemotherapy (-19.1 ± 3.1% vs. -16.5 ± 5.1%, p = 0.04). DSE, performed in 21 patients after a median of 166 months from the end of cancer treatment, detected new contractility disorders in 1 patient (4.8%) and decreased LVCR in the majority of patients when determined using changes in LVEF or LV GLS, and in all patients when assessed with changes in Force. Conclusions: Most asymptomatic mediastinal lymphoma survivors showed preserved ventricular function on resting echocardiography. However, all of them showed impaired LV contractile reserve on DSE, as assessed with a simple parameter-Force. This may indicate subtle LV dysfunction and confirms the need for long-term monitoring of patients with potentially cardiotoxic cancer treatment.

Deep phenotype characterization of hypertensive response to exercise: implications on functional capacity and prognosis across the heart failure spectrum

AIMS

Limited evidence is available regarding the role of hypertensive response to exercise (HRE) in heart failure (HF). We evaluated the systolic blood pressure (SBP) to workload slope during exercise across the HF spectrum, investigating haemodynamic and prognostic correlates of HRE.

METHODS AND RESULTS

We prospectively enrolled 369 patients with HF Stage C (143 had preserved [HFpEF], and 226 reduced [HFrEF] ejection fraction), 201 subjects at risk of developing HF (HF Stages A-B), and 58 healthy controls. We performed a combined cardiopulmonary exercise stress echocardiography testing. We defined HRE as the highest sex-specific SBP/workload slope tertile in each HF stage. Median SBP/workload slope was 0.53 mmHg/W (interquartile range 0.36-0.72); the slope was 39% steeper in women than men (p < 0.0001). After adjusting for age and sex, SBP/workload slope in HFrEF (0.47, 0.30-0.63) was similar to controls (0.43, 0.35-0.57) but significantly lower than Stages A-B (0.61, 0.47-0.75) and HFpEF (0.63, 0.42-0.86). Patients with HRE showed significantly lower peak oxygen consumption and peripheral oxygen extraction. After a median follow-up of 16 months, HRE was independently associated with adverse outcomes (all-cause mortality and hospitalization for cardiovascular reasons: hazard ratio 2.05, 95% confidence interval 1.81-5.18), while rest and peak SBP were not. Kaplan-Meier analysis confirmed a worse survival probability in Stages A-B (p = 0.005) and HFpEF (p < 0.001), but not HFrEF.

CONCLUSION

A steeper SBP/workload slope is associated with impaired functional capacity across the HF spectrum and could be a more sensitive predictor of adverse events than absolute SBP values, mainly in patients in Stages A-B and HFpEF.

Hypertrophic Cardiomyopathy as an Unexpected Mimic of Inducible Laryngeal Obstruction: The Case for Cardiopulmonary Exercise Testing in Otolaryngology

INTRODUCTION

Inducible laryngeal obstruction is a common and challenging cause of exertional dyspnea. We report a case of an unanticipated cardiac condition that presented with symptoms suggestive of inducible laryngeal obstruction.

DISCUSSION

A 55-year-old man was evaluated for progressive exertional dyspnea and throat tightness, unexplained after multiple medical evaluations. Resting laryngeal examination was suspicious for laryngopharyngeal reflux and mild vocal fold adduction during quiet expiration. Given progressive and refractory symptoms, maximal cardiopulmonary exercise testing with intermittent laryngeal examination was performed. This study excluded laryngeal causes of exercise limitation and led to an unexpected diagnosis of persistent atrial flutter and hypertrophic cardiomyopathy.

CONCLUSION

Cardiopulmonary exercise testing with laryngeal examination can identify unexpected and life-threatening mimics of inducible laryngeal obstruction that may be missed by unmonitored exercise challenges. Suspicion for inducible laryngeal obstruction at rest may not predict the true nature of exercise limitation on cardiopulmonary exercise testing.

Hypotension on cardiopulmonary stress test predicts 90 day mortality after LVAD implantation in INTERMACS 3-6 patients

AIMS

Cardiopulmonary stress test (CPX) is routinely performed when evaluating patient candidacy for left ventricular assist device (LVAD) implantation. The predictive value of hypotensive systolic blood pressure (SBP) response during CPX on clinical outcomes is unknown. This study aims to determine the effect of hypotensive SBP response during to clinical outcomes among patients who underwent LVAD implantation.

METHODS AND RESULTS

This was a retrospective single center study enrolling consecutive patients implanted with a continuous flow LVAD between 2011 and 2022. Hypotensive SBP response was defined as peak exercise SBP below the resting value. Multivariable Cox-regression analysis was performed to evaluate the relationship between hypotensive SBP response and all-cause mortality within 30 and 90 days of LVAD implantation. A subgroup analysis was performed for patients implanted with a HeartMate III (HM III) device. Four hundred thirty-two patients underwent LVAD implantation during the pre-defined period and 156 with INTERMACS profiles 3-6 met our inclusion criteria. The median age was 63 years (IQR 54-69), and 52% had ischaemic cardiomyopathy. Hypotensive SBP response was present in 35% of patients and was associated with increased 90 day all-cause mortality (unadjusted HR 9.16, 95% CI 1.98-42; P = 0.0046). Hazard ratio remained significant after adjusting for age, INTERMACS profile, serum creatinine, and total bilirubin. Findings were similar in the HM III subgroup.

CONCLUSIONS

Hypotensive SBP response on pre-LVAD CPX is associated with increased perioperative and 90 day mortality after LVAD implantation. Additional studies are needed to determine the mechanism of increased mortality observed.

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.

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.

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.

Higher Ventricular Premature Complex Burden is Associated with Lower Systolic Blood Pressure Response

Background

Ventricular premature complexes (VPCs) with a burden higher than 10% to 20% of total daily heart beats can cause VPC-induced cardiomyopathy. The systolic blood pressure response (SBPR) is the difference between the SBP during maximal exercise and rest. A low SBPR was recently identified to be a marker of cardiomyopathy. The aim of this manuscript was to clarify the association between VPC burden and SBPR.

Methods

From January to December 2015, all patients with a VPC burden larger than 240 beats/day on Holter recordings and treadmill exercise tests were enrolled. The patients with a heart rhythm other than sinus rhythm, coronary artery disease, and severe cardiomyopathy were excluded. The SBPR was measured during a treadmill test. The basic characteristics and echocardiographic findings were collected.

Results

All patients were classified into three groups: Group 1; 240-1,000 VPCs/day (n = 78), Group 2; 1,000-10,000 VPCs/day (n = 54), and Group 3; > 10,000 VPCs/day (n = 21). Group 1 had a higher SBPR than the other groups. Multivariate analysis revealed that only VPC burden was associated with SBPR. Receiver operating characteristic curve analysis showed that a VPC burden > 1,055 beats/day predicted a SBPR < 40 mmHg. The results were consistent in all subgroups. There were no significant differences in echocardiographic findings among the groups.

Conclusions

AVPC burden higher than 1,055 beats/day was associated with a reduced SBPR.

Cardiorespiratory Fitness and Cardiovascular Disease Prevention: an Update

PURPOSE OF REVIEW

Cardiovascular diseases account for nearly one third of all deaths globally. Improving exercise capacity and cardiorespiratory fitness (CRF) has been an important target to reduce cardiovascular events. In addition, the American Heart Association defined decreased physical activity as the fourth risk factor for coronary artery disease. Multiple large cohort studies have evaluated the impact of CRF on outcomes. In this review, we will discuss the role of CRF in reducing cardiovascular morbidity and mortality.

RECENT FINDINGS

Recent data suggest that CRF has an important role in reducing not only cardiovascular and all-cause mortality, but also incident myocardial infarction, hypertension, diabetes, atrial fibrillation, heart failure, and stroke. Most recently, its role in cancer prevention started to emerge. CRF protective effects have also been seen in patients with prior comorbidities like prior coronary artery disease, heart failure, depression, end-stage renal disease, and stroke. The prognostic value of CRF has been demonstrated in various patient populations and cardiovascular conditions. Higher CRF is associated with improved survival and decreased incidence of cardiovascular diseases (CVD) and other comorbidities including hypertension, diabetes, heart failure, and atrial fibrillation.

Atrial Fibrillation and Cardiovascular Outcomes in the Elderly

BACKGROUND

Prior studies have not examined which cardiovascular outcomes most frequently develop in participants with atrial fibrillation (AF) from population-based cohorts of the elderly.

METHODS

This analysis included 4,304 (85% white; 61% women) participants from the Cardiovascular Health Study who were free of baseline cardiovascular disease. AF cases were identified at baseline and as time-updated events during follow-up. Kaplan-Meier estimates were used to compute the 1-, 5-, 10-, and 15-year cumulative incidence rates of the following outcomes: coronary heart disease (CHD), myocardial infarction (MI), heart failure, and ischemic stroke. Cox regression was used to compute hazard ratios (HR) and 95% confidence intervals (CI) for the association between AF and each outcome.

RESULTS

For all time periods, the cumulative incidence estimates of CHD, MI, heart failure, and ischemic stroke were higher for those with AF compared with those without AF. Heart failure was the most frequent outcome in those with AF, while CHD events were the most frequently detected outcome in participants without AF. Compared with persons who did not have AF, the risk of heart failure was higher in those with AF (HR = 3.18, 95% CI = 2.78-3.64), and the magnitude of this association was greater than the other outcomes of interest (CHD: HR = 1.76, 95% CI = 1.54-2.03; MI: 1.40, 95% CI = 1.14-1.71; ischemic stroke: HR = 1.98, 95% CI = 1.63-2.39).

CONCLUSIONS

AF is associated with several adverse cardiovascular outcomes and heart failure is the most frequently detected event. Potentially, risk factor modification strategies for the primary prevention of heart failure will reduce the morbidity and mortality associated with AF.

The prognostic value of non-perfusion variables obtained during vasodilator stress myocardial perfusion imaging

Myocardial perfusion imaging (MPI) is an established diagnostic test that provides useful prognostic data in patients with known or suspected coronary artery disease. In more than half of the patients referred for stress testing, vasodilator stress is used in lieu of exercise. Unlike exercise, vasodilator stress does not provide information on exercise and functional capacity, heart rate recovery, and chronotropy, and ECG changes are less frequent. These non-perfusion data provide important prognostic and patient management information. Further, event rates in patients undergoing vasodilator MPI are higher than in those undergoing exercise MPI and even in those with normal images probably due to higher pretest risk. However, there are a number of non-perfusion variables that are obtained during vasodilator stress testing, which have prognostic relevance but their use has not been well emphasized. The purpose of this review is to summarize the prognostic values of these non-perfusion data obtained during vasodilator MPI.