Pulsatility of ascending aorta and restenosis after coronary angioplasty in patients >60 years of age with stable angina pectoris

The International Database of Central Arterial Properties for Risk Stratification: Research Objectives and Baseline Characteristics of Participants

OBJECTIVE

To address to what extent central hemodynamic measurements, improve risk stratification, and determine outcome-based diagnostic thresholds, we constructed the International Database of Central Arterial Properties for Risk Stratification (IDCARS), allowing a participant-level meta-analysis. The purpose of this article was to describe the characteristics of IDCARS participants and to highlight research perspectives.

METHODS

Longitudinal or cross-sectional cohort studies with central blood pressure measured with the SphygmoCor devices and software were included.

RESULTS

The database included 10,930 subjects (54.8% women; median age 46.0 years) from 13 studies in Europe, Africa, Asia, and South America. The prevalence of office hypertension was 4,446 (40.1%), of which 2,713 (61.0%) were treated, and of diabetes mellitus was 629 (5.8%). The peripheral and central systolic/diastolic blood pressure averaged 129.5/78.7 mm Hg and 118.2/79.7 mm Hg, respectively. Mean aortic pulse wave velocity was 7.3 m per seconds. Among 6,871 participants enrolled in 9 longitudinal studies, the median follow-up was 4.2 years (5th-95th percentile interval, 1.3-12.2 years). During 38,957 person-years of follow-up, 339 participants experienced a composite cardiovascular event and 212 died, 67 of cardiovascular disease.

CONCLUSIONS

IDCARS will provide a unique opportunity to investigate hypotheses on central hemodynamic measurements that could not reliably be studied in individual studies. The results of these analyses might inform guidelines and be of help to clinicians involved in the management of patients with suspected or established hypertension.

Central blood pressure for the management of hypertension: Is it a practical clinical tool in current practice?

Since noninvasive central blood pressure (BP) measuring devices are readily available, central BP has gained growing attention regarding its clinical application in the management of hypertension. The disagreement between central and peripheral BP has long been recognized. Some previous studies showed that noninvasive central BP may be better than the conventional brachial BP in association with target organ damages and long-term cardiovascular outcomes. Recent studies further suggest that the central BP strategy for confirming a diagnosis of hypertension may be more cost-effective than the conventional strategy, and guidance of hypertension management with central BP may result in less use of medications to achieve BP control. Despite the use of central BP being promising, more randomized controlled studies comparing central BP-guided therapeutic strategies with conventional care for cardiovascular events reduction are required because noninvasive central and brachial BP measures are conveniently available. In this brief review, the rationale supporting the utility of central BP in clinical practice and relating challenges are summarized.

Association between central haemodynamics and risk of all-cause mortality and cardiovascular disease: a systematic review and meta-analysis

The aim of this meta-analysis of longitudinal studies was to obtain a valid and cogent assessment of predictive value of central haemodynamic variables for cardiovascular outcomes and all-cause mortality. We searched for eligible articles using MEDLINE, CINAHL, EMBASE and Web of Science between 1 January 1969 and 31 December 2017. We finally included 24 prospective cohort studies, comprising 146,986 individuals for this analysis. Adjusted pooled hazard ratio of total cardiovascular events was 1.10 (95% confidence interval [CI] 1.04-1.16) for a 10 mmHg increase of central systolic pressure, 1.12 (95% CI 1.05-1.19) for a 10 mmHg increase of central pulse pressure and 1.18 (95% CI 1.09-1.27) for a 10% increase of central augmentation index. Furthermore, pooled hazard ratio of all-cause mortality was 1.22 (95% CI 1.14-1.31) for a 10 mmHg increase of central pulse pressure and 1.19 (95% CI 1.05-1.34) for a 10% increase of central augmentation index. Central haemodynamic variables are independent predictors of cardiovascular disease and all-cause mortality. This finding supports the notion that central pressure components and indices could be suitably implemented in clinical practice.

Effect of omega-3 polyunsaturated fatty acid supplementation on central arterial stiffness and arterial wave reflections in young and older healthy adults

Increased central arterial stiffness and enhanced arterial wave reflections may contribute to increased risk of cardiovascular disease development with advancing age. Omega-3 polyunsaturated fatty acid (n-3) ingestion may reduce cardiovascular risk via favorable effects exerted on arterial structure and function. We determined the effects of n-3 supplementation (4 g/day for 12 weeks) on important measures of central arterial stiffness (carotid-femoral pulse wave velocity; PWV) and arterial wave reflection (central augmentation index) in young (n = 12; 25 ± 1-year-old, mean ± SE) and older (n = 12; 66 ± 2) healthy adults. We hypothesized that n-3 supplementation would decrease carotid-femoral PWV and central augmentation index in older adults. Our results indicate that carotid-femoral PWV and central augmentation index were greater in older (988 ± 65 cm/sec and 33 ± 2%) than in young adults (656 ± 16 cm/sec and 3 ± 4%: both P < 0.05 compared to older) before the intervention (Pre). N-3 supplementation decreased carotid-femoral PWV in older (∆-9 ± 2% Precompared to Post; P < 0.05), but not young adults (∆2 ± 3%). Central augmentation index was unchanged by n-3 supplementation in young (3 ± 4 vs. 0 ± 4% for Pre and Post, respectively) and older adults (33 ± 2 vs. 35 ± 3%). Arterial blood pressure at rest, although increased with age, was not altered by n-3 supplementation in young or older adults. Collectively, these data indicate that 12 weeks of daily n-3 supplementation decreases an important measure of central arterial stiffness (carotid-femoral PWV) in older, but not young healthy adults. The mechanism underlying decreased central arterial stiffness with n-3 supplementation is unknown, but appears to be independent of effects on arterial blood pressure or arterial wave reflections.

A high normal thyroid-stimulating hormone is associated with arterial stiffness, central systolic blood pressure, and 24-hour systolic blood pressure in males with treatment-naïve hypertension and euthyroid

BACKGROUND

We compared the results of laboratory examinations, echocardiography, arterial stiffness, central blood pressure (BP) and ambulatory BP monitoring (ABPM) between treatment-naïve patients with low normal thyroid-stimulating hormone (TSH) and those with high normal TSH levels.

METHODS

A total of 285 consecutively-eligible patients with both treatment-naïve hypertension and euthyroid were divided into two groups: those with low-normal TSH (0.40-1.99 μIU/mL, group 1) and high-normal TSH (2.00-4.50 μIU/mL, group 2) and compared according to group and gender.

RESULTS

Males were divided into group 1 (n = 113, 68.9%) and group 2 (n = 51, 31.1%) and females were divided into group 1 (n = 71, 58.7%) and group 2 (n = 50, 41.3%). Multivariate analyses revealed that the augmentation index (71.0 [adjusted mean] ± 1.7 [standard error] vs. 78.8 ± 2.5%, P = 0.045), central systolic BP (SBP) (143.3 ± 2.1 vs. 153.0 ± 3.2 mmHg, P = 0.013), systemic vascular resistance (SVR, 21.4 ± 0.6 vs. 23.9 ± 0.9 mmHg/L/min, P = 0.027), SBP during daytime (144.1 ± 1.4 vs. 151.6 ± 2.1 mmHg, P=0.004) and nighttime (130.4 ± 1.6 vs. 138.5 ± 2.5 mmHg, P=0.008), and nighttime pulse pressure (PP, 47.2 ± 0.9 vs. 51.7 ± 1.4 mmHg, P = 0.010) were significantly higher while cardiac output (5.4 ± 0.1 vs. 4.8 ± 0.2L/min, P = 0.043) and PP amplification (1.02 ± 0.02 vs. 0.94 ± 0.03, P = 0.039) were significantly lower in the male group 2 than in the male group 1. However, there were no significant differences between the two groups in females.

CONCLUSIONS

Treatment-naïve hypertensive males with high normal TSH and euthyroid showed higher arterial stiffness, central SBP, SVR, and SBP in ABPM and lower cardiac output and PP amplification as compared to the the low normal TSH group, but not females.

Beyond blood pressure: Arterial stiffness as a new biomarker of cardiovascular disease

Arterial stiffness of the large, elastic conduit arteries is considered a risk marker of vascular aging, as well as a new biomarker of cardiovascular (CV) disease. Arterial stiffness also plays an important role in the development of isolated systolic hypertension (ISH) in the middle-aged and elderly population. ISH is characterized by an increase in pulse pressure (PP) in association with a rise in systolic blood pressure (SBP) and a fall in diastolic blood pressure (DBP). Increased PP, however, is not always a good surrogate for arterial stiffening because of the frequent discrepancy between peripheral brachial and central aortic PP values due to varying pressure amplification. Therefore, noninvasive, easily performed methods for more direct measurement of arterial stiffness and wave reflection, such as aortic pulse wave velocity (PWV) and pulse wave analysis, have been developed for clinical use. The present review aims to provide an understanding of the pathophysiology of arterial stiffness and wave reflection, to review the various techniques for their measurement, and to explore their usefulness in predicting CV risk and therapeutic benefit in comparison with traditional brachial artery cuff blood pressure (BP) by sphygmomanometry.

Prediction of cardiovascular events and all-cause mortality with central haemodynamics: a systematic review and meta-analysis

AIMS

To calculate robust quantitative estimates on the predictive value of central pressures and derived central haemodynamic indices for cardiovascular (CV) outcomes and all-cause mortality by meta-analysis of longitudinal studies.

METHODS AND RESULTS

We meta-analysed 11 longitudinal studies that had employed measures of central haemodynamics and had followed 5648 subjects for a mean follow-up of 45 months. The age- and risk-factor-adjusted pooled relative risk (RR) of total CV events was 1.088 (95% CI 1.040-1.139) for a 10 mmHg increase of central systolic pressure, 1.137 (95% CI 1.063-1.215) for a 10 mmHg increase of central pulse pressure (PP), and 1.318 (95% CI 1.093-1.588) for a 10% absolute increase of central augmentation index (AIx). Furthermore, we found that a 10% increase of central AIx was associated with a RR of 1.384 (95% CI 1.192-1.606) for all-cause mortality. When compared with brachial PP, central PP was associated with marginally but not significantly higher RR of clinical events (P = 0.057).

CONCLUSION

Central haemodynamic indexes are independent predictors of future CV events and all-cause mortality. Augmentation index predicts clinical events independently of peripheral pressures, while central PP has a marginally but not significantly (P = 0.057) better predictive ability when compared with peripheral PP.

Central blood pressure and hypertension: role in cardiovascular risk assessment

Although the differences between central and peripheral BP (blood pressure) have been known for decades, the consequences of decision-making based on peripheral rather than central BP have only recently been recognized. The influence of cyclic stretch (owing to cyclic changes in BP) on the aortic wall in atherosclerosis has been documented at every stage of its development. Apart from mediating atherosclerosis progression and plaque instability, the pulsatile component of BP is the main mechanism leading to plaque rupture and, consequently, to acute coronary syndromes and other vascular complications. The principal goal of the present review is to evaluate the role of central BP measurements, principally systolic and pulse pressure, for cardiovascular risk assessment. Recent findings suggest that the pulsatile component of BP (when represented by central pulse pressure or central pulsatility) is one of the most important factors determining event-free survival. Results of several prospective studies (using both invasive and non-invasive measurements of central BP) indicate not only an independent predictive value of central pulse pressure, but also its advantage over brachial pressure. Recent evidence suggests that some antihypertensive drugs can influence central BP more consistently when compared with peripheral BP. This is especially true for agents acting on the renin–angiotensin system. Nevertheless, large prospective studies aiming at the comparison of the predictive value of peripheral and central BP in the general population, as well as studies comparing the effectiveness of hypertension management based on peripheral compared with central BP measurements, are needed before algorithms based on central BP can be recommended for clinical practice.

Pulsatile but not steady component of blood pressure predicts cardiovascular events in coronary patients

Although the differences between central and peripheral blood pressure (BP) values have been known for decades, the consequences of decision making based on peripheral rather than central BP have only recently been recognized. There are only a few studies assessing the relationship between intraaortic BP and cardiovascular risk. In addition, the relationship between central BP and the risk of cardiovascular events in a large group of coronary patients has not yet been evaluated. Therefore, the aim of the study was to determine the prognostic significance of central BP-derived indices in patients undergoing coronary angiography. Invasive central BPs were taken at baseline, and study end points were ascertained during over a 4.5-year follow-up in 1109 consecutive patients. The primary end point (cardiovascular death or myocardial infarction or stroke or cardiac arrest or heart transplantation or myocardial revascularization) occurred in 246 (22.2%) patients. Central pulsatility was the most powerful predictor of the primary end point (hazard ratio [HR] 1.30, 95% confidence interval [CI] 1.14 to 1.48). Central pulse pressure was also independently related to the primary end point (HR 1.25, 95% CI 1.09 to 1.43). Central mean BP as well as peripheral BP parameters were not independently related to the primary end point risk. Central pulsatility was also related to risk of cardiovascular death or myocardial infarction or stroke. The pulsatile component of BP is the most important factor related to the cardiovascular risk in coronary patients. It is more closely associated with cardiovascular risk than steady component of BP.

Central arterial pressure and arterial pressure pulse: new views entering the second century after Korotkov

The ubiquitous brachial cuff method gained widespread clinical acceptance for blood pressure recording after confirmation of its prognostic value in 1917. This method displaced radial pulse waveform analysis by sphygmography, which also gave prognostic Information but was difficult to use. Since that time, brachial cuff sphygmomanometry has migrated from the physician's office to 24-hour monitoring and home use, with electronic methods replacing the Korotkov sound technique for determining systolic and diastolic pressure. Detailed instrumental studies, required by regulatory bodies, revealed inaccuracies of all cuff methods for recording true intra-arterial pressure. A major source of inaccuracy in assessing left ventricular load is the amplification of the pressure wave in its transit from the central aorta to upper limb arteries, as extensively studied by Earl H. Wood at the Mayo Clinic in Rochester, Minn, in the 1950s. This limitation can be overcome by combining newer methods using radial artery waveform analysis in conjunction with conventional cuff sphygmomanometry to noninvasively measure the central aortic pressure waveforms. Recent studies using radial tonometry have proved that this is more effective than conventional manometry in predicting cardiovascular events and gauging response to therapy. Measurement of central as well as peripheral arterial pressure and physiology is becoming increasingly used as an office practice and a laboratory procedure.

Ascending aortic blood pressure-derived indices are not correlated with the extent of coronary artery disease in patients with impaired left ventricular function

BACKGROUND

Ascending aortic blood pressure-derived indices were shown to be related to coronary atherosclerosis. Unfortunately, most studies published so far included patients with preserved left ventricular function. Therefore, the aim of the present study was to investigate the relation between ascending aortic blood pressure-derived indices and the extent of coronary atherosclerosis in patients with impaired left ventricular function.

METHODS

The study group consisted of 375 patients (302 men and 73 women; mean age: 59.0+/-10.1 years) with angiographically confirmed coronary artery disease and ejection fraction < or =55%. Invasive ascending aortic blood pressure during catheterization and conventional sphygmomanometer measurements were taken.

RESULTS

None of the brachial or aortic blood pressure-derived indices differed between patients with one-, two- and three-vessel coronary artery disease. They were not independently related to the risk of having three-vessel coronary artery disease in none of the constructed models in logistic regression analysis. Moreover, none of the studied indices was correlated with Gensini or severity scores. We also did not find any significant correlation between blood pressure-derived indices and extent of coronary atherosclerosis in patients with ejection fraction < or =25%, 25-40% or >40%.

CONCLUSION

Ascending aortic blood pressure-derived indices are not correlated with the severity of coronary atherosclerosis in patients with coronary artery disease and impaired left ventricular function.

Mean aortic pressure is the geometric mean of systolic and diastolic aortic pressure in resting humans

The aim of our study was twofold: 1) to establish a mathematical link between mean aortic pressure (MAP) and systolic (SAP) and diastolic aortic pressures (DAP) by testing the hypothesis that either the geometric mean or the harmonic mean of SAP and DAP were reliable MAP estimates; and 2) to critically evaluate three empirical formulas recently proposed to estimate MAP. High-fidelity pressures were recorded at rest at the aortic root level in controls (n = 31) and in subjects with various forms of cardiovascular diseases (n = 108). The time-averaged MAP and the pulse pressure (PP = SAP - DAP) were calculated. The MAP ranged from 66 to 160 mmHg [mean = 107.9 mmHg (SD 18.2)]. The geometric mean, i.e., the square root of the product of SAP and DAP, furnished a reliable estimate of MAP [mean bias = 0.3 mmHg (SD 2.7)]. The harmonic mean was inaccurate. The following MAP formulas were also tested: DAP + 0.412 PP (Meaney E, Alva F, Meaney A, Alva J, and Webel R. Heart 84: 64, 2000), DAP + 0.33 PP + 5 mmHg [Chemla D, Hébert JL, Aptecar E, Mazoit JX, Zamani K, Frank R, Fontaine G, Nitenberg A, and Lecarpentier Y. Clin Sci (Lond) 103: 7-13, 2002], and DAP + [0.33 + (heart rate x 0.0012)] PP (Razminia M, Trivedi A, Molnar J, Elbzour M, Guerrero M, Salem Y, Ahmed A, Khosla S, Lubell DL. Catheter Cardiovasc Interv 63: 419-425, 2004). They all provided accurate and precise estimates of MAP [mean bias = -0.2 (SD 2.9), -0.3 (SD 2.7), and 0.1 mmHg (SD 2.9), respectively]. The implications of the geometric mean pressure strictly pertained to the central (not peripheral) level. It was demonstrated that the fractional systolic (SAP/MAP) and diastolic (DAP/MAP) pressures were reciprocal estimates of aortic pulsatility and that the SAP times DAP product matched the total peripheral resistance times cardiac power product. In conclusion, although the previously described thumb-rules applied, the "geometric MAP" appears more valuable as it established a simple mathematical link between the steady and pulsatile component of aortic pressure.

Ascending aortic, but not brachial blood pressure-derived indices are related to coronary atherosclerosis

A recent study has demonstrated that pulse pressure (PP) measured in the ascending aorta is related to the extent of coronary artery disease in patients undergoing coronary angioplasty. However, no study so far has analyzed the relation between pulsatility of the ascending aorta and the extent of coronary artery disease in consecutive patients undergoing coronary angiography. Therefore, we investigated the relation between ascending aorta pulsatility and the extent of coronary atherosclerosis in unselected patients with angiographically confirmed coronary artery disease. The study group consisted of 423 consecutive patients (334 men and 89 women; mean age: 58.6+/-9.7 years) with angiographically confirmed coronary artery disease and ejection fraction < or =60% PP, fractional pulse pressure (the ratio of pulse pressure to mean pressure, FPP), and the ratio of pulse pressure to diastolic pressure (pulsatility index, PI) derived from intraaortic measurements differentiated patients with one-, two- and three-vessel coronary artery disease (PP, 63.0+/-16.0 versus 64.2+/-18.3 versus 71.8+/-19.1 mmHg (P < 0.0001); FPP, 0.68+/-0.14 versus 0.69+/-0.15 versus 0.76+/-0.17 (P < 0.0001); PI 0.89+/-0.25 versus 0.92+/-0.27 versus 1.04+/-0.32 (P < 0.0001)). After multivariate stepwise adjustment, the odds ratio (OR) and confidence interval (CI) of having three-vessel disease was: PP per 10 mmHg OR 1.15 (95% CI 1.02-1.31); FPP per 0.1 OR 1.18 (95% CI 1.02-1.37); and PI per 0.1 OR 1.11 (95% CI 1.03-1.21). None of brachial blood pressure indices was independently related to the extent of coronary atherosclerosis.

CONCLUSION

Pulse pressure, fractional pulse pressure, and pulsatility index of the ascending aorta are related to the risk of three-vessel disease in patients with coronary artery disease and preserved left ventricular function.

Determination of central aortic systolic and pulse pressure from the radial artery pressure waveform

OBJECTIVE

Measurements of central aortic systolic and pulse pressure, either gauged directly or estimated indirectly, have been shown to be superior to brachial pressure in outcome studies. While the radial pressure convolution method has proved to satisfy the criteria for 'substantial equivalence' to measure central pressure non-invasively, this study sought simpler methods to generate central systolic and pulse pressure directly from the radial artery waveform.

METHODS

Two sets of data were used, in which radial artery pressure waves were measured by applanation tonometry and ascending aortic pressure was generated by the SphygmoCor process. Different approaches were applied to each dataset: firstly, using the time period from wave foot to systolic peak in central arteries; secondly, through identifying the pressure surge from the reflected wave in the radial artery; and thirdly from extrapolation and calibration of carotid systolic pressure when mean and diastolic pressure considered to be equal with radial values.

RESULTS

Both datasets showed good correspondence between the central systolic and pulse pressure obtained with each of the three approaches and respective pressures generated by SphygmoCor process; all were within AAMI SP10 criteria and grade A for BSH criteria.

CONCLUSION

All three approaches gave results similar substantially equivalent to those obtained with the SphygmoCor system for aortic, systolic and pulse pressure. Hence, simple inspection of the radial waveform has the potential to improve the estimation of aortic systolic and pulse pressure.

Ascending aortic blood pressure waveform may be related to the risk of coronary artery disease in women, but not in men

Recent studies have demonstrated that fractional pulse pressure and fractional diastolic pressure are related to the risk of coronary artery disease. However, the effect of the ascending aortic pressure waveform on the risk of coronary artery disease in men and women analyzed separately has not been reported. The objective of the study was to assess the relation between ascending aortic blood pressure waveform and the presence of coronary artery disease in men and in women. The study group consisted of 447 patients (302 men and 145 women; mean age: 57.6+/-9.8 years) with preserved left ventricular function who were undergoing first diagnostic coronary angiography. After multivariate stepwise adjustments, the odds ratio (OR) and confidence interval (CI) of having coronary artery disease in women was (OR are reported for standard deviation increase in each variable): pulse pressure OR 1.61 (95% CI 1.06-2.46); fractional systolic pressure OR 1.72 (95% CI 1.08-2.71); fractional diastolic pressure OR 0.58 (95% CI 0.37-0.92); fractional pulse pressure OR 1.72 (95% CI 1.08-2.71); and pulsatility index OR 1.74 (95% CI 1.09-2.78). None of the studied variables was independently related to the presence of coronary artery disease in men. In conclusion, fractional systolic and diastolic pressure, pulse pressure, fractional pulse pressure and the ratio of pulse pressure to diastolic pressure may be independently related to the risk of coronary artery disease in women, but not in men.