Karina Gonzalez Carta

Impact of Cardiorespiratory Fitness on Frequency of Atrial Fibrillation, Stroke, and All-Cause Mortality

Benefits of cardiorespiratory fitness on cardiovascular health are well recognized, but the impact on incidence of atrial fibrillation (AF) and stroke, and, particularly, risk of stroke and mortality in patients with AF is less clear. From 1993 to 2010, patients referred for a treadmill exercise test (TMET) at the Mayo Clinic Rochester, MN, were retrospectively identified (N = 76,857). From this, 14,094 local residents were selected. Exclusions were age <18 years; history of heart failure, structural or valvular heart disease, AF or flutter, or stroke. Subjects were divided into 4 groups at baseline based on quartiles of functional aerobic capacity (FAC) and followed through January 2016. The final study cohort included 12,043 patients. During median follow-up of 14 (9 to 17) years, 1,222 patients developed incident AF, 1,128 developed stroke, and 1,590 patients died. Each 10% increase in FAC was associated with decreased risk of incident AF, stroke, and mortality by 7% (0.93 [0.91 to 0.96, p < 0.001]), 8% (0.92 [0.89 to 0.94, p < 0.001]), and 16% (0.84 [0.82 to 0.86, p < 0.001]), respectively. In patients who developed incident AF with baseline FAC <75% versus ≥105%, risks of both stroke (1.40 [1.04 to 1.90, p = 0.01]) and mortality (3.20 [2.11 to 4.58, p < 0.001]) were significantly higher. In conclusion, better cardiorespiratory fitness is associated with lower risk of incident AF, stroke, and mortality. Similarly, risk of stroke and mortality in patients with AF is also inversely associated with cardiorespiratory fitness.

Prognostic Performance of Heart Rate Recovery on an Exercise Test in a Primary Prevention Population

Background Heart rate (HR) recovery has been investigated in specific patient cohorts, but there is less information about the role of HR recovery in general populations. We investigated whether HR recovery has long‐term prognostic significance in primary prevention. Methods and Results Exercise tests performed between 1993 and 2010 on patients aged 30 to 79 years without cardiovascular disease were included. Mortality was determined from Mayo Clinic records and Minnesota Death Index. Total, cardiovascular, and non‐cardiovascular mortality was reported according to HR recovery <13 bpm using Cox regression. 19 551 patients were included, 6756 women (35%), age 51±10 years. There were 1271 deaths over follow‐up of 12±5 years. HR recovery declined after age 60, and was also lower according to diabetes mellitus, hypertension, obesity, current smoking, and poor cardiorespiratory fitness but not sex or β‐blockers. Adjusting for these factors, abnormal HR recovery was a significant predictor of total (hazard ratio [95% confidence interval]=1.56 [1.384–1.77]), cardiovascular (1.95 [1.57–2.42]), and non‐cardiovascular death (1.41 [1.22–1.64]). Hazard ratios for cardiovascular death according to abnormal HR recovery were significant in all age groups (30–59, 60–69, 70–79), in both sexes, in patients with and without hypertension, obesity, and diabetes mellitus, but not in patients taking β‐blockers, current smokers, and patients with normal cardiorespiratory fitness. Conclusions HR recovery is a powerful prognostic factor predicting total, cardiovascular, and non‐cardiovascular death in a primary prevention cohort. It performs consistently well according to sex, age, obesity, hypertension, and diabetes mellitus but shows diminished utility in patients taking β‐blockers, current smokers, and patients with normal cardiorespiratory fitness.

MYOCARDITIS, HEART FAILURE AND ARRHYTHMIAS IN PATIENTS WITH ZIKA

Backround: Zika virus infection is a mosquito-borne disease that has caused an explosive pandemic throughout the Americas. Local transmission has been found in USA; there are no reports of cardiovascular (CV) manifestation of Zika. This study sought to describe the occurrence of CV involvement of

Significance of an Increase in Diastolic Blood Pressure During a Stress Test in Terms of Comorbidities and Long-Term Total and CV Mortality

BACKGROUND A decrease in diastolic blood pressure (DBP) with exercise is considered normal, but the significance of an increase in DBP has not been validated. Our aim was to determine the relationship of DBP increasing on a stress test regarding comorbidities and mortality. METHODS Our database was reviewed from 1993 to 2010 using the first stress test of a patient. Non-Minnesota residence, baseline cardiovascular (CV) disease, rest DBP <60 or >100 mm Hg, and age <30 or ≥80 were exclusion criteria. DBP response was classified: normal if peak DBP-rest DBP < 0, borderline 0-9, and abnormal ≥10 mm Hg. Mortality was determined from Mayo Clinic records and Minnesota Death Index. Logistic regression was used to determine the relationship of DBP response to the presence of comorbidities. Cox regression was used to determine total and CV mortality risk by DBP response. All analyses were adjusted for age, sex, and resting DBP. RESULTS Twenty thousand seven hundred sixty patients were included (51 ± 11 years, female n = 7,314). Rest/peak averaged DBP 82 ± 8/69 ± 15 mm Hg in normal vs. 79 ± 9/82 ± 9 mm Hg in borderline vs. 76 ± 9/92 ± 11 mm Hg in abnormal DBP response. There were 1,582 deaths (8%) with 557 (3%) CV deaths over 12 ± 5 years of follow-up. In patients with borderline and abnormal DBP response, odds ratios for obesity, hypertension, diabetes, and current smoking were significant, while hazard ratios for total and CV death were not significant compared with patients with normal DBP response. CONCLUSIONS DBP response to exercise is significantly associated with important comorbidities at the time of the stress test but does not add to the prognostic yield of stress test.

Effect of Cardiorespiratory Fitness on Co-Morbidities and Mortality in Never, Past, and Current Smokers

Smoking is a strong risk factor for cardiovascular (CV) disease and mortality, but quitting may cause weight gain and increase the risk of co-morbidities. Our aim was to investigate the effect of smoking and exercise on weight-associated co-morbidities and mortality. We included Minnesota residents without baseline CV disease who underwent exercise testing from 1993 to 2010. Mortality was determined from Mayo Clinic records and Minnesota Death Index. Total, CV and cancer mortality by smoking status and cardiorespiratory fitness (CRF): (1) <80%, (2) 80% to 99%, (3) ≥100%. Differences were tested using logistic and Cox regression adjusting for age and gender. A total of 21,981 patients (7,090 past, 2,464 current smokers) were included. Past smokers had more obesity, hypertension, diabetes, and low CRF compared with never smokers. Current smokers did not show increased risk factor prevalence compared with never smokers but had higher rates of low CRF. There were 1,749 deaths; mean follow-up was 12 ± 5 years. Mortality was only slightly increased in past versus never smokers (Hazard Ratio: 1.2; 95% confidence interval 1.12 to 1.38) but was much higher in current smokers (Hazard Ratio 2.4; 95% confidence interval 2.05 to 2.80). Mortality in never, past, and current smokers was inversely related to CRF level. In conclusion, past smokers showed higher rates of co-morbidities and low CRF, but mortality was only mildly increased versus never smokers, whereas current smokers carried a high mortality risk. Our data suggest that quitting smoking is beneficial despite the increased co-morbidities. Exercise may potentially mitigate the risk of co-morbidities and death in those who quit smoking.

ACUTE CORONARY SYNDROMES DURING ENDURANCE SPORTS: OLMSTED COUNTY EXPERIENCE

Background: Sudden death rates have been recorded for endurance sports such as long-distance running. Acute coronary syndromes (ACS) producing myocardial ischemia have been documented to account for approximate 16% of sudden death cases – with the majority of these cases being reversible by CPR/

EXERCISE TEST PREDICTS BOTH CARDIOVASCULAR AND NON-CARDIOVASCULAR MORTALITY IN PATIENTS WITHOUT CARDIOVASCULAR DISEASE

Background: Exercise test variables have been shown to predict total mortality in several cardiovascular (CV) diseases. Is this because cardiovascular mortality constitutes many of the deaths in the published studies, or may these prognostic factors also predict non-CV mortality? Our aim was to

CARDIOVASCULAR FITNESS REDUCES THE RISK OF WEIGHT-ASSOCIATED COMORBIDITIES AND ALL-CAUSE MORTALITY IN PAST SMOKERS

Smoking is a powerful risk factor for cardiovascular disease (CVD) and mortality, but quitting may cause weight gain and increase in comorbidities. Our aim was to study if better functional aerobic capacity (FAC) on a stress test is associated with lower risk of obesity, diabetes, hypertension, and