Secular trends in coronary atherosclerosis--analysis in patients with valvular regurgitation

Prediction of obstructive coronary artery disease in patients undergoing heart valve surgery: A cross-sectional study in a tertiary care hospital

Introduction: Estimating the probability of obstructive coronary artery disease in patients undergoing noncoronary cardiac surgery should be considered compulsory. Our study sought to evaluate the prevalence of obstructive coronary artery disease in patients undergoing valvular heart surgery and to utilize predictive methodology of concomitant obstructive coronary artery disease in these patients. Methods: The retrospective study cohort was derived from a tertiary care hospital registry of patients undergoing coronary angiogram prior to valvular heart operations. Decision tree, logistic regression, and support vector machine models were built to predict the probability of the appearance of obstructive coronary artery disease. A total of 367 patients from 2016 to 2019 were analyzed. Results: The mean age of the study population was 57.3±9.3 years, 45.2% of the patients were male. Of 367 patients, 76 (21%) patients had obstructive coronary artery disease. The decision tree, logistics regression, and support vector machine models had an area under the curve of 72% (95% CI: 62% - 81%), 67% (95% CI: 56% - 77%), and 78% (95% CI: 68% - 87%), respectively. Multivariate analysis indicated that hypertension (OR 1.98; P=0.032), diabetes (OR 2.32; P=0.040), age (OR 1.05; P=0.006), and typical angina (OR 5.46; P<0.001) had significant role in predicting the presence of obstructive coronary artery disease. Conclusion: Our study revealed that approximately one-fifth of patients who underwent valvular heart surgery had concomitant obstructive coronary artery disease. The support vector machine model showed the highest accuracy compared to the other model.

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

Heart valve disease in elderly

The incidence of heart valve disease increases significantly with age. Degenerative abnormalities associated with severe aortic stenosis and mitral and tricuspid regurgitation are found in not less than 10% of the population aged ≥ 75 years. Surgical treatment has been considered for years to be the treatment of choice. However, it was not uncommonly associated with high perioperative morbidity and mortality due to frequent comorbidities and overall frailty conditions of these patients. Conventional risk scores such as Society of Thoracic Surgeons and European System for Cardiac Operative Risk Evaluation may underestimate the risk of surgery in elderly patients, leading to inappropriate surgical indication. On the other hand, at least 30% of patients with severe conditions are left untreated due to prohibitive surgical risk. Interventional procedures, which are in continuous development, may be actually considered for high risk patients and, as recent results suggest, also for intermediate risk patients.

Prevalence and Prediction of Obstructive Coronary Artery Disease in Patients Undergoing Primary Heart Valve Surgery

Background

The prevalence of coronary artery disease (CAD) in valvular patients is similar to that of the general population, with the usual association with traditional risk factors. Nevertheless, the search for obstructive CAD is more aggressive in the preoperative period of patients with valvular heart disease, resulting in the indication of invasive coronary angiography (ICA) to almost all adult patients, because it is believed that coronary artery bypass surgery should be associated with valve replacement.

Objectives

To evaluate the prevalence of obstructive CAD and factors associated with it in adult candidates for primary heart valve surgery between 2001 and 2014 at the National Institute of Cardiology (INC) and, thus, derive and validate a predictive obstructive CAD score.

Methods

Cross-sectional study evaluating 2898 patients with indication for heart surgery of any etiology. Of those, 712 patients, who had valvular heart disease and underwent ICA in the 12 months prior to surgery, were included. The P value < 0.05 was adopted as statistical significance.

Results

The prevalence of obstructive CAD was 20%. A predictive model of obstructive CAD was created from multivariate logistic regression, using the variables age, chest pain, family history of CAD, systemic arterial hypertension, diabetes mellitus, dyslipidemia, smoking, and male gender. The model showed excellent correlation and calibration (R² = 0.98), as well as excellent accuracy (ROC of 0.848; 95%CI: 0.817-0.879) and validation (ROC of 0.877; 95%CI: 0.830 - 0.923) in different valve populations.

Conclusions

Obstructive CAD can be estimated from clinical data of adult candidates for valve repair surgery, using a simple, accurate and validated score, easy to apply in clinical practice, which may contribute to changes in the preoperative strategy of acquired heart valve surgery in patients with a lower probability of obstructive disease.

Intraoperative imaging to detect coronary stenosis in no-angiography patients

Sometimes, patients scheduled for cardiac operations other than coronary artery bypass may be unsuitable for preoperative coronary angiography. We routinely use intraoperative high-resolution epicardial ultrasound to select the proper target for the graft and to check graft anastomosis integrity. We describe 3 patients who could not undergo preoperative coronary angiography for different reasons. In all cases, we discovered significant stenosis in the left anterior descending coronary artery, which required bypass grafting. Intraoperative verification by transit-time flow measurements confirmed the significant stenosis detected by imaging.

Acute chest pain in contingency operations at a Role 1 facility

Acute chest pain is a common medical presenting complaint which can be difficult to diagnose and treat outside of a fully equipped emergency department. In future contingency operations the number of personnel deployed is likely be smaller, with the medical cover appropriate for the population at risk, such that the deployed medical facilities will be smaller than the Role 3 unit with which we have become familiar over the last 10 years of operations in Afghanistan. Physician involvement in these smaller medical facilities is crucial to maintain clinical effect when dealing with patients presenting with disease and non-battle injury, which can often make up the majority of deployed healthcare work. Patients presenting with chest pain require rapid assessment and stabilisation prior to medical evacuation to a suitable definitive care unit. This article focuses on emergency acute chest pain presentations, non-cardiac causes of chest pain, risk reduction and how contingency will affect patient care.

Heart failure in adult congenital heart disease

OPINION STATEMENT

Adult congenital heart disease (ACHD) patients represent a special population in modern cardiology: though their numbers are growing, and they represent a high-resource utilization subgroup, a robust evidence-base of randomized trials is lacking. Much of the standard therapy is adapted from the treatment of ischemic and idiopathic left ventricle systolic failure, with a small, but growing body of evidence on medical therapy in select ACHD diagnoses. At our institution, for instance, there is a long tradition of using angiotensin antagonists in patients with a systemic right ventricle to prevent deleterious remodeling. The effects of beta-blockers on functional class in ACHD are yet unproven, but there is promising data on pulmonary vasodilators. Control of coronary risk factors and aerobic exercise should be considered for all. Prevention of arrhythmias is important, and multi-site pacing is an emerging therapy. New prognostic tools including natriuretic peptides and CPET are increasingly used to guide earlier initiation of these therapies.

Molecular studies on coronary artery disease-a review

Coronary artery disease (CAD) remains the major cause of mortality and morbidity in the entire world population. The conventional risk factors of CAD include hypertension, hyperlipidemia, diabetes mellitus, family history, smoking etc. These factors contribute only 50 % of the total risk of CAD. For providing a complete risk assessment in CAD, it is mandatory to have well-planned clinical, biochemical and genetic studies in patients with CAD and subjects who are at risk of developing CAD. In this review an attempt is made to critically evaluate the conventional and emerging risk factors which predispose the individual to CAD. Specifically, the molecular basis of CAD including high oxidative stress, low antioxidant status and increased DNA damage are covered. A comprehensive and multifactorial approach to the problem is the better way to reduce the morbidity and mortality of the disease.

Burden of coronary artery disease in adults with congenital heart disease and its relation to congenital and traditional heart risk factors

As adult patients with congenital heart disease (CHD) grow older, the risk of developing coronary artery disease (CAD) increases. We sought to estimate the prevalence of CAD in adult patients with CHD, the safety of coronary angiography in this setting, and the potential relation of CAD to clinical and hemodynamic parameters. Two hundred fifty adult patients with CHD (mean age 51 +/- 15 years; 53% men) underwent selective coronary angiography in our center for reasons other than suspected CAD. Clinical and hemodynamic data were retrieved retrospectively from medical records and echocardiographic and angiographic databases, respectively. Significant CAD using quantitative coronary angiography was found in 9.2% of adult patients with CHD. No patient with cyanosis or age <40 years had significant CAD. Systolic and diastolic systemic ventricular dimensions were significantly higher in patients with CAD, even after adjustment for age (odds ratio [OR] for 10-mm increase 2.59, 95% confidence interval [CI] 1.29 to 5.21, p = 0.007; OR 2.31, 95% CI 1.24 to 4.31, p = 0.008, respectively). Systemic arterial hypertension and hyperlipidemia were strong predictors of CAD (OR 4.54, 95% CI 1.82 to 12.0, p = 0.001; OR 9.08, 95% CI 3.56 to 24.54, p <0.0001, respectively), whereas no relation to chest pain was found. Only 1 major adverse event was recorded during coronary angiography. In conclusion, the prevalence of significant CAD in a hospital adult CHD cohort was similar to that in the general population. This study supported the performance of selective coronary angiography in patients >40 years referred for cardiac surgery, with low risk of major complications. Traditional cardiovascular risk factors for CAD also applied to adult patients with CHD, in whom primary prevention of CAD was as important as in the general population.

Surgical Correction of Mitral Regurgitation in the Elderly

Background— In the elderly, mitral regurgitation (MR) is frequent, but surgery risks are considered high. Benefits and indications of MR surgery are uncertain in the elderly.

Methods and Results— Baseline characteristics, outcome, and trends for surgical results improvement were analyzed in elderly patients (≥75 years of age; n=284) operated on for MR in 1980 to 1995 compared with younger patients (65 to 74 years of age, n=504; and <65 years of age, n=556). Preoperatively, class III to IV symptoms, atrial fibrillation, coronary disease, creatinine, and comorbidity index were more severe in elderly patients (all P <0.002). In the long term after surgery, observed survival stratified by age (≥75, 65 to 74, <65 years) was lower in elderly than in younger patients (at 5 years, 57±3%, 73±2%, and 85±2%, respectively; P <0.001), but ratios of observed to expected survival were similar (83%, 85%, and 88%, respectively). In multivariate analysis adjusted to expected survival, elderly patients showed no difference in life expectancy restoration compared with younger patients (adjusted hazard ratio, 0.89; 95% confidence interval, 0.73 to 1.30; P =0.54). Temporal trends showed that risk of operative mortality, although higher in elderly patients ( P <0.001), declined markedly for all ages (27% to 5% in those ≥75 years of age, P <0.01; 21% to 4% in those 65 to 74 years of age, P <0.01; and 7% to 2% in those <65 years of age, P =0.06), with a parallel decline in low cardiac output and length of hospital stay. Over time, valve repair feasibility increased in all age groups (30% to 84% overall and 31% to 93% in degenerative MR; P <0.0001).

Conclusions— Elderly patients undergoing MR surgery display more severe preoperative characteristics and incur higher operative risks than younger patients. However, restoration of life expectancy after surgery is similar in elderly and younger patients, and outstanding recent surgical improvements particularly benefited elderly patients. Thus, elderly patients with MR can now carefully be considered for surgery before refractory heart failure is present.

Perspectives on Dyslipidemia and Coronary Heart Disease in Women

Coronary heart disease (CHD) remains the leading cause of death among American women. Numerous differences exist between younger and older women and between women and men with respect to the pathology of CHD and its incidence and prevalence over the life cycle. Differences in lipoprotein levels and lipid fractions play an important role in CHD risk. Hormonal influences on lipoprotein levels in women are complex, change throughout the life span, and are influenced by the administration of oral contraceptives and hormone replacement therapy. Women with obesity, metabolic syndrome, or diabetes have lipid profiles that adversely affect CHD risk. To date, no randomized trials testing the impact of lifestyle changes on lipoprotein levels and subsequent CHD events in non-institutionalized women have been performed, and women have not been well represented in clinical end point trials of pharmacologic lipid-lowering therapy. Available evidence suggests that lipid-lowering therapy with statins does provide benefit in reducing the risk of coronary events in women; however, women remain undertreated, and more data are needed to determine optimal cardiovascular prevention and treatment in this population.

Stroke and ischemic heart disease mortality trends in Brazil from 1979 to 1996

Stroke and ischemic heart disease (IHD) mortality rates were analyzed in Brazilian subjects older than 30 years of age from 1979 to 1996. Population estimates were based on census surveys. Mortality data were obtained from the Ministry of Health. For stroke, the age-adjusted death rate (ADR) dropped from 200 to 164 and from 168 to 130 deaths/100,000 population in men and women, respectively (p < 0.001), in the interval study. For IHD, the ADR dropped from 194 to 164 and from 119 to 105 deaths/100,000 population in men and women, respectively (p < 0.001), in the same time period. Mortality from stroke and IHD combined was greater in men for all age groups (p < 0.001). Stroke was the most frequent cause of death in both women and men except for men aged between 40 and 69 years, in whom IHD was more common. Stroke and IHD were the main causes of death in the Brazilian population.

Elevated serum lipoprotein(a) level is an independent marker of severity of thoracic aortic atherosclerosis

STUDY OBJECTIVE

Lipoprotein(a) (Lp[a]) level is a risk factor for ischemic heart disease, cerebrovascular disease, and peripheral vascular disease. However, few data are available concerning the relationship between Lp(a) level and severity of thoracic aortic atherosclerosis. We hypothesized in this transesophageal echocardiography (TEE) study that Lp(a) level is a marker of severity of thoracic aortic atherosclerosis.

DESIGN

Cross-sectional study.

SETTING

University hospital.

PATIENTS

Risk factors, coronary angiographic features, and TEE findings were analyzed prospectively in 119 patients with valvular disease.

MEASUREMENTS AND RESULTS

The following risk factors were recorded: age, gender, hypertension, smoking, lipid parameters, diabetes, body mass index, and family history of coronary artery disease. Serum levels of Lp(a) were measured for each patient. By univariate analysis, age, diabetes, hypertension, smoking, Lp(a), total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol levels were significant predictors of thoracic aortic atherosclerosis. There was a positive and significant correlation between the Lp(a) levels and the score of severity of thoracic aortic atherosclerosis (p = 0.0001). Multivariate regression analysis revealed that Lp(a) was an independent predictor of severity of thoracic aortic atherosclerosis (p = 0.0001).

CONCLUSION

This prospective study indicates that serum Lp(a) level is an independent marker of severity of thoracic aortic atherosclerosis detected by multiplane TEE. These findings emphasize the role of Lp(a) as a marker of atherosclerotic lesions in the major arterial locations.

Plasma homocysteine and severity of thoracic aortic atherosclerosis

STUDY OBJECTIVES

Plasma homocysteine level is a risk factor for coronary events, stroke, and peripheral atherosclerotic disease. However, few data are available concerning the relationship between homocysteine level and severity of thoracic aortic atherosclerosis. We hypothesized in this multiplane transesophageal echocardiography (TEE) study that homocysteine level is a marker of the presence and severity of thoracic aortic atherosclerosis.

DESIGN

Cross-sectional study.

SETTING

University hospital.

PATIENTS

Risk factors, angiographic features, and TEE findings were analyzed prospectively in 82 valvular patients.

MEASUREMENTS AND RESULTS

The following risk factors were recorded: age, gender, hypertension, smoking, lipid parameters, diabetes, body mass index, and family history of coronary artery disease. Plasma levels of homocysteine, vitamin B(12), and folic acid were measured for each patient. By univariate analysis, age, diabetes, hypertension, smoking, family history of coronary artery disease, and levels of homocysteine, total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol were significant predictors of the presence of thoracic aortic plaques. There was a positive correlation between the plasma homocysteine levels and the score of severity of thoracic atherosclerosis (r = 0.48; p = 0.0001) as well as between the homocysteine levels and the grades of severity of aortic intimal changes (p = 0.0008). Multivariate regression analysis revealed that homocysteine was an independent predictor of the presence and severity of thoracic aortic atherosclerosis.

CONCLUSION

This prospective study indicates that plasma homocysteine level is a marker of severity of thoracic atherosclerosis detected by multiplane TEE. These findings emphasize the role of homocysteine as a marker of atherosclerotic lesions in the major arterial locations.

Exercise echocardiographic assessment in severe mitral regurgitation

In chronic severe mitral regurgitation, minimum morbidity and mortality is achieved by applying surgical correction before left ventricular dysfunction becomes irreversible. This requires detection of subtle signs of early ventricular decompensation, for which isotonic stress echocardiography is more accurate than is use of resting indices of contractile function alone. We perform serial 6-monthly stress echocardiography for patients with severe mitral regurgitation, and recommend surgery when the exercise end-systolic volume index or ejection fraction reaches the cutoff values in Table 4 or if there is a clear adverse trend. Exercise echocardiography is more accurate than is exercise electrocardiography for detecting concomitant coronary disease prior to revascularization. Stress testing is also an objective measure of symptoms. Color-Doppler stress echocardiography can detect those patients whose mitral regurgitation worsens (or even develops de novo) with exercise, which can explain unexpected symptoms. Stress echocardiography, therefore, provides a comprehensive and cost-effective evaluation of patients with mitral regurgitation that combines functional, diagnostic, and prognostic information.

Relation between low-density lipoprotein cholesterol and thoracic aortic atherosclerosis

This prospective study, which included 320 patients, showed that total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, total cholesterol/high-density lipoprotein cholesterol, and triglycerides correlate with thoracic aortic atherosclerosis. Low-density lipoprotein cholesterol is identified as an independent predictor of thoracic aortic plaque related to the severity of thoracic aortic atherosclerosis.

Correlation of thoracic aortic atherosclerotic plaque detected by multiplane transesophageal echocardiography and cardiovascular risk factors

This study of 416 patients identified age, male gender, smoking, diabetes, hypertension, and hypercholesterolemia as independent predictors of thoracic aortic atherosclerotic plaque. Age, smoking, hypercholesterolemia, hypertension, and diabetes were predictors of the severity and extent of thoracic aortic atherosclerosis.

[Preoperative coronarography in heart valve disease patients. A probability analysis of coronary lesion]

INTRODUCTION AND OBJECTIVES

The indication of preoperative coronary angiography is routinely performed for patients who are going to valve replacement surgery. The need of coronary angiography is based on age, gender and previous angina, but it is not usually based on risk factors. The purpose of this study has been to find markers to predict the probability of coronary lesion in this group of patients.

PATIENTS AND METHODS

We studied retrospectively a population of 541 patients with valvular heart disease who underwent preoperative coronary angiography from 1989 to 1994. Mean age was 61.8 (range 34-82). There were 301 men and 240 women. We analyzed in each patient different variables such as age, gender, previous angina, hypertension, diabetes mellitus, tobacco and familial predisposition. We correlated these variables with the presence of coronary lesion by multivariate analysis.

RESULTS

There were 73 patients with coronary lesion greater than 50%. The prevalence of significant coronary artery disease was 13.4%. Angina was present in 34.6%. The risk of coronary lesion was defined as odds ratio: previous angina 3.3; tobacco 2.6; diabetes 2.2; hypertension 1.8 and age 1.4. The others variables were not predictor of coronary lesion. The probability of coronary lesion in patients without those variables (angina, tobacco, diabetes, hypertension) was 4%. If we analyzed age, the probability of coronary lesion was 3% in patients under 65 years and 6% above 65 years.

CONCLUSIONS

The lack of previous angina and at least the three risk factors described as predictors of coronary lesion (hypertension, tobacco and diabetes) can define a group of patients with a very low prevalence of coronary lesion, especially if they are under 65 years. It can allow us to avoid preoperatory coronary angiography in patients who undergo valve replacement.

Epidemiology of risk in hypertensives: experience in treated patients

Knowledge of the epidemiology of cardiovascular disease (CVD) in hypertensive patients derives primarily from observation of populations composed largely of untreated subjects. Increasingly, however, individuals with elevated blood pressure are treated. An 18-year observational study of 8690 participants in a systematic hypertension control project reveals that cardiovascular events continue to be the principal morbid and mortal outcomes. Over time, the incidence of stroke and heart attack remained stable, whereas congestive heart failure (CHF), as a first event, increased tenfold after 10 years. Diabetes and evidence of vascular disease at entry predicted morbidity. Persisting cardiovascular morbidity in the face of satisfactory blood pressure control suggests the need for additional preventive intervention.

Distribution and determinants of cardiovascular events during 20 years of successful antihypertensive treatment

OBJECTIVE

To define the distribution and determinants of cardiovascular disease events among participants undergoing long-term antihypertensive therapy, and to stratify them into risk groups on the basis of pretreatment clinical profiles.

DESIGN

A prospective cohort study of participants in a worksite-based antihypertensive treatment program in New York city (1973-1994).

PATIENTS

We studied 8690 systematically treated patients who had at least 6 months of follow-up (average of 5.7 years) and, at entry, had had a systolic blood pressure of > or = 160 mmHg or a diastolic blood pressure of > or = 95 mmHg (after 1992 > or = 140/90 mmHg), or had been being administered antihypertensive medication.

MAIN OUTCOME MEASURES

Blood pressure and incidence of morbid and mortal cardiovascular events.

RESULTS

Blood pressure control (to 140 +/- 3/87 +/- 7 mmHg) was achieved by the first year and maintained through 18 years of therapy. In nearly 50,000 person-years of follow-up, there were 468 cardiovascular disease events [myocardial infarction including revascularization (282), strokes (93), congestive heart failure (30) and other cardiovascular deaths (63)]. Deaths from cardiovascular disease events accounted for 68% of all deaths. Myocardial infarction was most common throughout, but congestive heart failure incidence surpassed stroke incidence after 10 years. A scheme for risk stratification was constructed after analysis of the independent association of baseline factors and incident cardiovascular events. Upon the basis of ease of ascertainment and their demonstrated associations with occurrence of cardiovascular disease during treatment, we selected five pretreatment factors (history of heart attack, stroke, diabetes, age > or = 55 years and pulse pressure > or = 60 mmHg) to stratify patients into four groups. Those with no risk factor had a low risk (n=2999), those with one had a moderate risk (3042), those with two had a high risk (2237), and those with three or more had a very high risk (412). Overall, the unadjusted rates of incidence of cardiovascular disease events per 1000 person-years for patients in very high and low risk groups differed by factors of six and 14 for men and women, respectively.

CONCLUSION

These results demonstrate that long-term control of blood pressure can be achieved in a general population. Nevertheless, cardiovascular disease events still accounted for most morbidity and mortality among these 'recovered' hypertensive patients. At entry, on the basis of readily identifiable characteristics, it was possible to stratify patients according to likelihood of subsequent events occurring despite control of blood pressure. This scheme could provide the basis for targeting more aggressive therapy where the potential for further cardioprotection is greatest.

Fibrinogen is an independent marker for thoracic aortic atherosclerosis

The fibrinogen level is an independent risk factor for coronary events and stroke, but no detailed data are available concerning fibrinogen and atherosclerotic disease of the thoracic aorta. This prospective study using multiplane transesophageal echocardiography examined the relation between atherosclerotic thoracic aortic plaque and fibrinogen level. One-hundred forty-eight patients (65 +/- 11 years) with valvular heart disease underwent multiplane transesophageal echocardiography and coronary angiography. We measured plasma fibrinogen level for each patient and recorded the following cardiovascular risk factors: age, sex, systemic hypertension, history of smoking, hypercholesterolemia, diabetes mellitus, body mass index, and family history of coronary artery disease (CAD). Patients with thoracic aortic plaque had a higher level of plasma fibrinogen (p = 0.0001), were older (p = 0.0001), and had significantly more risk factors: history of smoking (p = 0.009), hypertension (p = 0.008), hypercholesterolemia (p = 0.0001), diabetes mellitus (p = 0.01), and family history of CAD (p = 0.003). Multivariate logistic regression analysis of fibrinogen level and risk factors revealed 4 independent predictors of thoracic aortic plaque: fibrinogen, age, hypercholesterolemia, and history of smoking. Fibrinogen was also an independent predictor of CAD. There was a relation between fibrinogen levels and the severity of aortic atherosclerosis (r = 0.46; p = 0.0001) and the severity of CAD (r = 0.30; p = 0.0001). This prospective study indicates that fibrinogen is an independent marker for thoracic aortic plaque related to the severity of thoracic aortic atherosclerosis and confirms that fibrinogen constitutes an independent marker for CAD related to the severity of angiographically evaluated coronary atherosclerosis.

Multiplane transoesophageal echocardiographic detection of thoracic aortic plaque is a marker for coronary artery disease in women

OBJECTIVE

This study was conducted to examine if the multiplane transoesophageal echocardiographic detection of atherosclerotic plaque in the thoracic aorta could predict the absence or the presence and the severity of significant coronary artery disease in women. Its association with coronary disease is attractive and may have great influence on foregoing routine preoperative cardiac catheterization in patients with valvular heart disease but no data are available in women.

METHODS

Clinical and angiographic features and transoesophageal echocardiographic findings were prospectively analysed in 111 women.

RESULTS

In 24 women with significant coronary disease, 20 had thoracic aortic plaque on transoesophageal echocardiographic studies. In contrast, aortic plaque existed in only 12 of the remaining 87 women with normal or mildly abnormal coronary arteries. Therefore, the presence of aortic plaque had a sensitivity of 83%, a specificity of 86%, a positive and negative predictive values of 62% and 95%, respectively for the detection of significant coronary disease. There was a significant relation between the severity and the extent of atherosclerotic lesions and the angiographic coronary score (P<0.0001). Multivariate logistic regression analysis revealed that aortic plaque was the most significant independent marker of coronary disease (odds ratio=27.9; 95% confidence interval=5.5-131.6; P<0.0001).

CONCLUSIONS

This prospective study indicates that multiplane transoesophageal echocardiographic examination of thoracic atherosclerotic plaque is a marker for coronary disease in women and especially a powerful predictor of absence of significant coronary artery disease. Transoesophageal echocardiographic aortic examination might be used with risk factors and angina symptoms to discuss the need for preoperative coronary angiography in women with valvular heart disease.

Effect of electrical stimulus parameters on the development and propagation of action potentials in short excitable fibres

Intracellular action potentials (IAPs) produced by short fibres in response to their electrical stimulation were analysed. IAPs were calculated on the basis of the Hodgkin-Huxley (1952) model by the method described by Joyner et al. (1978). Principal differences were found in processes of activation of short (semilength L less than 5 lambda) and long fibres under near-threshold stimulation. The shorter the fibre, the lower was the threshold value (Ithr). Dependence of the latency on the stimulus strength (Ist) was substantially non-linear and was affected by the fibre length. Both fibre length and stimulus strength influenced the IAP amplitude, the instantaneous propagation velocity (IPV) and the site of the first origin of the IAP (and, consequently, excitability of the short fibre membrane). With L less than or equal to 2 lambda and Ithr less than or equal to Ist less than or equal to 1.1Ithr, IPV could reach either very high values (so that all the fibre membrane fired practically simultaneously) or even negative values. The latter corresponded to the first origin of the propagated IAP, not at the site of stimulation but at the fibre termination or at a midpoint. The characters of all the above dependencies were unchanged irrespective of the manner of approaching threshold (variation of stimulus duration or its strength). Reasons for differences in processes of activation of short and long fibres are discussed in terms of electrical load and latency. Applications of the results to explain an increased jitter, velocity recovery function and velocity-diameter relationship are also discussed.