Robert J. Doonan

The effect of smoking on arterial stiffness

A systematic literature review was conducted using PubMed, Embase and the Cochrane Library to determine the effect of acute, chronic and passive smoking on arterial stiffness and to determine whether these effects are reversible after smoking cessation. A total of 39 relevant studies were identified and included. Acute smoking was found to cause an acute increase in arterial stiffness. Similarly, passive smoking increased arterial stiffness acutely and chronically. The majority of studies identified chronic smoking as a risk factor for increasing arterial stiffness. However, some studies found no statistical difference in arterial stiffness between nonsmokers and long-term smokers, although chronic smoking seems to sensitize the arterial response to acute smoking. In addition, whether arterial stiffness is reversed after smoking cessation and the timeline in which this may occur could not be determined from the identified literature. The effect of smoking discontinuation on arterial stiffness remains to be established by prospective smoking cessation trials.

The association between preeclampsia and arterial stiffness.

A systematic review and meta-analysis was conducted using MEDLINE, EMBASE, and the Cochrane Library to investigate the association between preeclampsia and arterial stiffness. Twenty-three relevant studies were included. A significant increase in all arterial stiffness indices combined was observed in women with preeclampsia vs. women with normotensive pregnancies [standardized mean difference 1.62, 95% confidence interval (CI) 0.73–2.50]; carotid–femoral pulse wave velocity (cfPWV) and augmentation index (AIx) were also significantly increased (weighted mean difference, WMDcfPWV 1.04, 95% CI 0.34–1.74; WMDAIx 15.10, 95% CI 5.08–25.11), whereas carotid–radial PWV (crPWV) increase did not reach significance (WMDcrPWV 0.99, 95% CI −0.07 to 2.05). Significant increases in arterial stiffness measurements were noted in women with preeclampsia compared with those with gestational hypertension. Arterial stiffness measurements may also be useful in predicting preeclampsia and may play a role in the increased risk of future cardiovascular complications seen in women with a history of preeclampsia.

Increased arterial stiffness in obstructive sleep apnea: a systematic review.

Obstructive sleep apnea is a prevalent disease that is associated with significant morbidity and mortality, particularly due to cardiovascular disease. An emerging cardiovascular risk factor, arterial stiffness, may also be involved in the cardiovascular complications of obstructive sleep apnea. The purpose of this review was to summarize the current literature regarding the effect of obstructive sleep apnea on arterial stiffness. We conducted a systematic literature review using PubMed, Embase and the Cochrane Library. We identified 24 studies that met search criteria investigating the effect of obstructive sleep apnea on arterial stiffness. Arterial stiffness was found to be increased in obstructive sleep apnea patients compared with controls or increased in severe compared with mild sleep apnea. In some studies, a positive correlation was identified between the degree of arterial stiffness and sleep apnea severity. In the two randomized, controlled trials and the two nonrandomized trials identified, treatment of obstructive sleep apnea with continuous positive airway pressure led to significant decreases in arterial stiffness. Obstructive sleep apnea appears to have an independent effect on arterial stiffness, which may be one of the mechanisms accounting for sleep apnea-associated cardiovascular risk.

Altered arterial stiffness and subendocardial viability ratio in young healthy light smokers after acute exercise.

Background Studies showed that long-standing smokers have stiffer arteries at rest. However, the effect of smoking on the ability of the vascular system to respond to increased demands (physical stress) has not been studied. The purpose of this study was to estimate the effect of smoking on arterial stiffness and subendocardial viability ratio, at rest and after acute exercise in young healthy individuals. Methods/Results Healthy light smokers (n = 24, pack-years = 2.9) and non-smokers (n = 53) underwent pulse wave analysis and carotid-femoral pulse wave velocity measurements at rest, and 2, 5, 10, and 15 minutes following an exercise test to exhaustion. Smokers were tested, 1) after 12h abstinence from smoking (chronic condition) and 2) immediately after smoking one cigarette (acute condition). At rest, chronic smokers had higher augmentation index and lower aortic pulse pressure than non-smokers, while subendocardial viability ratio was not significantly different. Acute smoking increased resting augmentation index and decreased subendocardial viability ratio compared with non-smokers, and decreased subendocardial viability ratio compared with the chronic condition. After exercise, subendocardial viability ratio was lower, and augmentation index and aortic pulse pressure were higher in non-smokers than smokers in the chronic and acute conditions. cfPWV rate of recovery of was greater in non-smokers than chronic smokers after exercise. Non-smokers were also able to achieve higher workloads than smokers in both conditions. Conclusion Chronic and acute smoking appears to diminish the vascular response to physical stress. This can be seen as an impaired ‘vascular reserve’ or a blunted ability of the blood vessels to accommodate the changes required to achieve higher workloads. These changes were noted before changes in arterial stiffness or subendocardial viability ratio occurred at rest. Even light smoking in young healthy individuals appears to have harmful effects on vascular function, affecting the ability of the vascular bed to respond to increased demands.

Differences in arterial stiffness at rest and after acute exercise between young men and women

There is controversy as to whether there are sex differences in arterial stiffness. Acute physical stress can elicit vascular abnormalities not present at rest. Our objective was to assess sex differences in arterial stiffness at rest and in response to acute physical stress. Healthy young men (n=67) and women (n=55) underwent pulse wave analysis and carotid-femoral pulse wave velocity measurements at rest and 2, 5, 10 and 15 min following an exercise test to exhaustion. At rest, aortic systolic, diastolic, pulse and mean pressures were all significantly higher in men as was aortic pulse pressure at 10 and 15 min post exercise and aortic systolic pressure at 15 min. Carotid-femoral pulse wave velocity was significantly higher in men (6.0±0.7 m s−1 vs. 5.6±0.6 m s−1, P=0.03) at rest and at all time points post exercise. Heart rate-adjusted augmentation index was significantly lower (−10.7±10.2% vs. −4.0±10.9, P<0.0001) and subendocardial viability ratio was significantly higher (176.2±43.8% vs. 163.4±40.9, P=0.04) in men at rest. To our knowledge, this is the first study to assess sex differences in the arterial stiffness response to acute physical stress in young men and women. Although we were not able to elicit differences in vascular function after adjustment, which were not present at rest, we found that young men and women exhibit differences in arterial stiffness at rest and after acute physical stress.

Three-dimensional imaging MS of lipids in atherosclerotic plaques: Open-source methods for reconstruction and analysis.

Three‐dimensional MALDI imaging MS (IMS) is a growing branch of IMS still requiring developments in methodology and technology to make the technique routinely accessible. Many challenges are simply a matter of producing 3D reconstructions and interpreting them in a timely fashion. In this aim and using analysis of lipids from atherosclerotic plaques from a human carotid and mouse aortic sinuses, we describe 3D reconstruction methods using open‐source software that provides high‐quality visualization and rapid interpretation through multivariate segmentation of the 3D IMS data. Multiple datasets were generated for each sample and we provide insight into simple means to correlate the separate datasets.

Undertreatment of hypercholesterolemia

Abstract Recent guidelines recommend strict goals for low-density lipoprotein cholesterol (LDL-C) (1.8–2.6 mmol/L; 70–100 mg/dL). However, these goals are not always met and many primary and secondary prevention patients are not optimally controlled. Both the under-prescription of lipid-lowering medication and lack of adherence to prescribed medications could account for this situation. In this issue of the journal, two studies evaluated the under-treatment of hypercholesterolemia in European countries, as well as patient/physician characteristics that are related to poor control of LDL-C. This editorial considers the implications of these findings. While we have come far in recent years in terms of treating hypercholesterolemia, we still have considerable room for improvement and progress towards evidence-based clinical practice.

Association of Ultrasonic Texture and Echodensity Features Between Sides in Patients with Bilateral Carotid Atherosclerosis

OBJECTIVES Our objective was to estimate the correlation of echodensity and textural features, using ultrasound and digital image analysis, between plaques in patients with bilateral carotid stenosis. DESIGN Cross-sectional observational study. METHODS Patients undergoing carotid endarterectomy were recruited from Vascular Surgery at the Royal Victoria and Jewish General hospitals in Montreal, Canada. Bilateral pre-operative carotid ultrasound and digital image analysis was performed to extract echodensity and textural features using a commercially available Plaque Texture Analysis software (LifeQMedical Ltd). Principal component analysis (PCA) was performed. Partial correlation coefficients for PCA and individual imaging variables between surgical and contralateral plaques were calculated with adjustment for age, sex, contralateral stenosis, and statin use. RESULTS In the whole group (n = 104), the six identified PCA variables and 42/50 individual imaging variables were moderately correlated (r = .211-.641). Correlations between sides were increased in patients with ≥50% contralateral stenosis and symptomatic patients. CONCLUSION Textural and echodensity features of carotid plaques were similar between two sides in patients with bilateral stenosis, supporting the notion that plaque instability is determined by systemic factors. Patients with unstable features of one plaque should perhaps be monitored more closely or treated more aggressively for their contralateral stenosis, particularly if this is hemodynamically significant.

The effect of oral contraceptive pills and the natural menstrual cYCLe on arterial stiffness and hemodynamICs (CYCLIC).

Background: Over 100 million women currently use oral contraceptive pills (OCPs) worldwide. However, little is known about the effects of OCPs on arterial stiffness and hemodynamics. Furthermore, whether arterial stiffness and hemodynamics vary throughout the natural menstrual cycle remains controversial. Herein, we estimated the effect of the natural menstrual cycle and OCP use on arterial stiffness and hemodynamics. Methods: Healthy, nonsmoking women, aged 18–30 years, were recruited if they had regular menstrual cycles and never used OCPs (OCP nonuser group), or were using low-dose OCPs for at least 6 months (OCP user group). Using applanation tonometry, three assessments of arterial stiffness and central and peripheral hemodynamics were performed in a randomized order: during the early follicular (days 3–6), late follicular (days 14–16), and luteal (days 22–26) phases. Within group and between group comparisons were performed using general linear models. Results: Sixty women (21.7 ± 2.8 years) were recruited. Compared with OCP nonusers, OCP users had significantly increased aortic and peripheral SBPs during the active OCP use, but not during the inert tablet phase. No differences in arterial stiffness were noted. Conclusion: OCP use was associated with significant increases in aortic and peripheral blood pressures, but not with increased arterial stiffness. Given the widespread OCP use, future longitudinal studies are needed to confirm our findings and assess the long-term effect of OCPs on arterial stiffness and hemodynamics.

Heart Rate Variability Exhibits Complication-Dependent Changes Postsurgery

“Surgical stress response” is tissue damage postsurgery, leading to a systemic response (inflammation, sympathetic upregulation, and release of vasoactive chemicals), which is typically measured by C-reactive protein (CRP). We assessed arterial stiffness and heart rate variability (HRV)—additional parameters reflecting autonomic and vascular functions—in this response and their potential associations with postoperative complications. In 47 participants undergoing abdominal surgery, CRP, arterial stiffness, and HRV were measured pre- and postoperatively (days 1 and 2). C-reactive protein was significantly higher postoperatively in participants experiencing complications but not preoperatively. Compared to participants without complications, those with complications had increased HRV and pnn50 (time domain) and tendency toward increasing low-frequency/high-frequency ratio (frequency domain) on postoperative day 2. Therefore, time and frequency domain HRV parameters show perioperative changes in relation to complication development. These findings suggest the applicability of this noninvasive technology to a variety of abdominal operations. Larger studies need to confirm these findings.