Comparison of baseline brachial artery measurements and effect on peak flow‐mediated dilation

Total brachial artery reactivity and incident heart failure and heart failure subtypes: multi-ethnic study of atherosclerosis

Endothelial dysfunction may be a phenotypic expression of heart failure (HF). Total brachial artery reactivity (TBAR) is a non-invasive measurement of endothelial function that has been associated with increased risk of cardiovascular outcomes. Limited information is currently available on the impact of TBAR on incident HF and its subtypes. The aim of this study was to investigate whether TBAR is associated with overall incident HF, and the two HF subtypes, HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF) in a community-based study. The sample included 5499 participants (45-84 years of age) from the Multi-Ethnic Study of Atherosclerosis who were free of cardiovascular disease at baseline. Brachial artery was imaged via ultrasound after five minutes of cuff occlusion at the right forearm. TBAR was calculated as the difference between maximum and minimum brachial artery diameters following cuff release, divided by the minimum diameter multiplied by 100%. A dichotomous TBAR variable was created based on the median value (below or above 7.9%). Participants with EF ≤ 40% were considered HFrEF and those with EF ≥ 50% were considered HFpEF. Cox proportional hazards regression models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI). Over a mean follow-up period of 12.5 years, incident HF was diagnosed in 250 participants: 98 classified as HFrEF, 106 as HFpEF, and 46 with unknown or borderline EF (41-49%). Crude analysis revealed that those with TBAR below the median had a significantly greater risk of HF (HR 1.46; 95% CI 1.13-1.88, p < 0.01) and HFrEF (HR 1.61; 95% CI 1.07-2.43, p < 0.05). Following adjustment for known HF risk factors (e.g., age, sex, race, blood pressure), the strength of these relationships was attenuated. Borderline significant results were revealed in those with HFpEF (HR 1.43; 95% CI 0.97-2.12, p = 0.06). Kaplan-Meier curves suggest significantly lower risks of developing HF and HFrEF in those with TBAR above the median (log-rank p ≤ 0.05 for both). When examined as a continuous variable, with a cut point of 50% for EF, every 1-standard deviation (9.7%) increase in TBAR resulted in a 19 and 29% decrease in risk of HF (p < 0.05) and HFrEF (p = 0.05), respectively. Lower TBAR values were associated with higher rates of incident HF and HFrEF, suggesting a possible role of endothelial dysfunction in HF pathogenesis. The impact of other known HF risk factors may mediate this relationship, thus further research is warranted.

Total brachial artery reactivity and first time incident coronary heart disease events in a longitudinal cohort study: The multi-ethnic study of atherosclerosis

Background

Brachial artery reactivity (BAR) is usually determined as the maximum brachial artery diameter (BAD) following release of an occluding pressure cuff compared to a BAD before cuff inflation. BAD early after cuff deflation can also serve as baseline for estimating total brachial artery reactivity (TBAR). We investigate whether TBAR is associated with first time coronary heart disease events.

Methods

Participants of the Multi-Ethnic Study of Atherosclerosis (n = 5499) consisting of whites, African-Americans, Chinese and Hispanics were followed longitudinally for a mean of 12.5 years. Brachial artery ultrasound was performed following five minutes of cuff occlusion at the forearm. TBAR was estimated from BAD following cuff release as the difference between maximum and minimum brachial artery diameters divided by the minimum diameter multiplied by 100%. TBAR was added to multivariable Cox proportional hazards models with Framingham risk factors as predictors and time to first coronary heart disease event as outcome.

Results

Average TBAR was 9.7% (9.7 SD). Mean age was 61.7 years, 50.9% women. Increased TBAR was associated with lower risk of CHD events with a hazard rate of 0.78 per SD increase (95% C.I. 0.67, 0.91; p = 0.001). A TBAR below the median of 7.87% (Inter Quartile Range: 4.16%, 13.0%) was associated with a 31% lower risk of coronary heart disease event (Hazard Ratio: 0.69; 95% C.I.: 0.55, 0.87).

Conclusion

TBAR is an independent predictor of first time coronary heart disease events and is exclusively measured after release of a blood pressure occlusion cuff.

High-intensity interval exercise attenuates but does not eliminate endothelial dysfunction after a fast food meal

We investigated whether two different bouts of high-intensity interval exercise (HIIE) could attenuate postprandial endothelial dysfunction. Thirteen young (27 ± 1 yr), nonexercise-trained men underwent three randomized conditions: 1) four 4-min intervals at 85-95% of maximum heart rate separated by 3 min of active recovery (HIIE 4 × 4), 2) 16 1-min intervals at 85-95% of maximum heart rate separated by 1 min of active recovery (HIIE 16 × 1), and 3) sedentary control. HIIE was performed in the afternoon, ~18 h before the morning fast food meal (1,250 kcal, 63g of fat). Brachial artery flow-mediated dilation (FMD) was performed before HIIE ( baseline 1), during fasting before meal ingestion ( baseline 2), and 30 min, 2 h, and 4 h postprandial. Capillary glucose and triglycerides were assessed at fasting, 30 min, 1 h, 2 h, and 4 h (triglycerides only). Both HIIE protocols increased fasting FMD compared with control (HIIE 4 × 4: 6.1 ± 0.4%, HIIE 16 × 1: 6.3 ± 0.5%, and control: 5.1 ± 0.4%, P < 0.001). For both HIIE protocols, FMD was reduced only at 30 min postprandial but never fell below baseline 1 or FMD during control at any time point. In contrast, control FMD decreased at 2 h (3.8 ± 0.4%, P < 0.001) and remained significantly lower than HIIE 4 × 4 and 16 × 1 at 2 and 4 h. Postprandial glucose and triglycerides were unaffected by HIIE. In conclusion, HIIE performed ~18 h before a high-energy fast food meal can attenuate but not entirely eliminate postprandial decreases in FMD. This effect is not dependent on reductions in postprandial lipemia or glycemia. NEW & NOTEWORTHY Two similar high-intensity interval exercise (HIIE) protocols performed ∼18 h before ingestion of a high-energy fast food meal attenuated but did not entirely eliminate postprandial endothelial dysfunction in young men largely by improving fasting endothelial function. Both HIIE protocols produced essentially identical results, suggesting high reproducibility of HIIE effects.

High-flow-mediated constriction in adults is not influenced by biomarkers of cardiovascular and metabolic risk

PURPOSE

During reactive hyperemia, the brachial artery in some individuals constricts prior to dilation. Our aim was to describe the frequency of high-flow-mediated constriction (H-FMC) in adults, and its relationship to body composition and biomarkers of cardiovascular and metabolic risk.

METHODS

Two hundred forty-six adults (124 male, 122 female; 36 ± 7 years old) were assessed for H-FMC via sonographic imaging of the brachial artery. Blood pressure, glucose, insulin, lipids, and body composition assessed via dual energy X-ray absorptiometry were collected. H-FMC was characterized as a 10-second average of maximal postocclusion constriction. Independent t test was used to compare H-FMC versus non-H-FMC individuals.

RESULTS

H-FMC was observed in approximately 69% of adult participants (54 obese, 57 overweight, and 59 normal weight). Total body mass (82.3 ± 17.5 versus 76.3 ± 16.3 kg, p = 0.012), fat mass (27.7 ± 11.5 versus 23.8 ± 10.5 kg, p = 0.012), body mass index (27.7 ± 4.9 versus 26.1 ± 5.0 kg/m² , p = 0.018), and low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio (2.41 ± 1.03 versus 2.09 ± 0.72, p = 0.007) were higher in H-FMC than in non-H-FMC individuals. Flow-mediated dilatation (FMD) (6.12 ± 3.48 versus 8.09 ± 3.02%, p < 0.001) was lower in H-FMC subjects. However, there was no difference in brachial artery dilation between groups (7.57 ± 3.69 versus 8.09 ± 3.02%, p = 0.250) when H-FMC was added to FMD.

CONCLUSIONS

Increased body mass, fat mass, and body mass index were associated with a greater H-FMC. When H-FMC was present, the FMD response to reactive hyperemia was significantly lower. Because H-FMC has been observed to negatively affect FMD response to reactive hyperemia, we suggest that H-FMC should be noted when analyzing and interpreting FMD data. H-FMC may be an ancillary measure of endothelial health. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:35-42, 2017.

Successful Use of the MYNXGRIP Closure Device during Repeated Transbrachial Percutaneous Peripheral Intervention

The use of closure devices after transbrachial arterial puncture is still controversial. Here we report on a case where the MYNXGRIP (AccessClosure Inc., Santa Clara, CA, USA) could be used successfully in a patient, who underwent percutaneous peripheral arterial intervention twice via transbrachial access.