Traditional and novel risk factors for incident aortic stenosis in community-dwelling older adults

OBJECTIVES

Calcific aortic stenosis (AS) is the most common valvular disease in older adults, yet its risk factors remain insufficiently studied in this population. Such studies are necessary to enhance understanding of mechanisms, disease management and therapeutics.

METHODS

The Cardiovascular Health Study is a population-based investigation of older adults that completed adjudication of incident AS over long-term follow-up. We evaluated traditional cardiovascular risk factors or disease, as well as novel risk factors from lipid, inflammatory and mineral metabolism pathways, in relation to incident moderate or severe AS (including AS procedures) and clinically significant AS (severe AS, including procedures).

RESULTS

Of 5390 participants (age 72.9±5.6 years, 57.6% female, 12.5% black), 287 developed moderate or severe AS, and 175 clinically significant AS, during median follow-up of 13.1 years. After full adjustment, age (HR=1.66 per SD (95% CI=1.45, 1.91)), male sex (HR=1.41 (1.06, 1.87)), diabetes (HR=1.53 (1.10, 2.13)), coronary heart disease (CHD, HR=1.36 (1.01, 1.84)), lipoprotein-associated phospholipase-A2 (LpPLA2) activity (HR=1.21 per SD (1.07, 1.37)) and sCD14 (HR=1.16 per SD (1.01, 1.34)) were associated with incident moderate/severe AS, while black race demonstrated an inverse association (HR=0.40 (0.24, 0.65)), and creatinine-based estimated glomerular filtration rate (eGFRcr) showed a U-shaped relationship. Findings were similar for clinically significant AS, although CHD and sCD14 fell short of significance, but interleukin-(IL) 6 showed a positive association.

CONCLUSION

This comprehensive evaluation of risk factors for long-term incidence of AS identified associations for diabetes and prevalent CHD, LpPLA2 activity, sCD14 and IL-6, and eGFRcr. These factors may hold clues to biology, preventive efforts and potential therapeutics for those at highest risk.

Bone mineral density and long-term progression of aortic valve and mitral annular calcification: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

Bone and mineral metabolism has been implicated in the pathophysiology of cardiac valve calcification. Whether bone demineralization, a common aging-related disorder, promotes calcific valve disease remains uncertain. We tested the hypothesis that low bone mineral density (BMD) is associated with greater incidence/progression of cardiac valve calcification in the Multi-Ethnic Study of Atherosclerosis.

METHODS

Using linear mixed-effects models, we related baseline measurement of BMD of the thoracic vertebrae by computed tomography (CT) in 6768 participants to serial CT assessments of aortic valve calcification (AVC) and mitral annular calcification (MAC) obtained over a >10-year period.

RESULTS

After multivariable adjustment, lower BMD (per SD decrement) was associated with accelerated increase in AVC over time in women (0.76 [95% CI 0.42,1.09] Agatston -units [AU]/year) and men (1.41 [95% CI 0.48,2.33] AU/year), as well as for MAC in women (3.22 [95% CI 1.16,5.28] AU/year) and men (3.59 [95% CI 2.09,5.09] AU/year). Significant effect modification was observed, with more pronounced BMD-related acceleration of AVC and MAC progression in older or white participants of one or both sexes, as well as by estimated glomerular filtration rate, though the latter differed by sex for AVC and MAC.

CONCLUSIONS

In this multi-ethnic cohort, low thoracic BMD was significantly, but modestly, associated with increased AVC and MAC progression. This suggests that altered bone mineral metabolism does not have a major impact on calcific valve disease in the general population, but the possibility of a more meaningful influence in higher-risk individuals with osteoporosis will require further investigation.

Cumulative burden of clinically significant aortic stenosis in community-dwelling older adults

OBJECTIVES

Current estimates of aortic stenosis (AS) frequency have mostly relied on cross-sectional echocardiographic or longitudinal administrative data, making understanding of AS burden incomplete. We performed case adjudications to evaluate the frequency of AS and assess differences by age, sex and race in an older cohort with long-term follow-up.

METHODS

We developed case-capture methods using study echocardiograms, procedure and diagnosis codes, heart failure events and deaths for targeted review of medical records in the Cardiovascular Health Study to identify moderate or severe AS and related procedures or hospitalisations. The primary outcome was clinically significant AS (severe AS or procedure). Assessment of incident AS burden was based on subdistribution survival methods, while associations with age, sex and race relied on cause-specific survival methods.

RESULTS

The cohort comprised 5795 participants (age 73±6, 42.2% male, 14.3% Black). Cumulative frequency of clinically significant AS at maximal 25-year follow-up was 3.69% (probable/definite) to 4.67% (possible/probable/definite), while the corresponding 20-year cumulative incidence was 2.88% to 3.71%. Of incident cases, about 85% had a hospitalisation for severe AS, but roughly half did not undergo valve intervention. The adjusted incidence of clinically significant AS was higher in men (HR 1.62 [95% CI 1.21 to 2.17]) and increased with age (HR 1.08 [95% CI 1.04 to 1.11]), but was lower in Blacks (HR 0.43 [95% CI 0.23 to 0.81]).

CONCLUSIONS

In this community-based study, we identified a higher burden of clinically significant AS than reported previously, with differences by age, sex and race. These findings have important implications for public health resource planning, although the lower burden in Blacks merits further study.

Return to play with hypertrophic cardiomyopathy: are we moving too fast? A critical review

The diagnosis of a potentially lethal cardiovascular disease in a young athlete presents a complex dilemma regarding athlete safety, patient autonomy, team or institutional risk tolerance and medical decision-making. Consensus cardiology recommendations previously supported the ‘blanket’ disqualification of athletes with hypertrophic cardiomyopathy (HCM) from competitive sport. More recently, epidemiological studies examining the relative contribution of HCM as a cause of sudden cardiac death (SCD) in young athletes and reports from small cohorts of older athletes with HCM that continue to exercise have fueled debate whether it is safe to play with HCM. Shared decision-making is endorsed within the sports cardiology community in which athletes can make an informed decision about treatment options and potentially elect to continue competitive sports participation. This review critically examines the available evidence relevant to sports eligibility decisions in young athletes diagnosed with HCM. Histopathologically, HCM presents an unstable myocardial substrate that is vulnerable to ventricular tachyarrhythmias during exercise. Studies support that young age and intense competitive sports are risk factors for SCD in patients with HCM. We provide an estimate of annual mortality based on our understanding of disease prevalence and the incidence of HCM-related SCD in different athlete populations. Adolescent and young adult male athletes and athletes participating in a higher risk sport such as basketball, soccer and American football exhibit a greater risk. This review explores the potential harms and benefits of sports disqualification in athletes with HCM and details the challenges and limitations of shared decision-making when all parties may not agree.

Do 'pathologic' cardiac murmurs in adolescents identify structural heart disease? An evaluation of 15 141 active adolescents for conditions that put them at risk of sudden cardiac death

OBJECTIVES

We assessed whether the presence and character of a cardiac murmur in adolescents were associated with structural heart disease that confers risk of sudden cardiac death (SCD).

METHODS

We performed a retrospective analysis of 15 141 adolescents age 12-19 who underwent a heart screen with history, physical examination and ECG. Participants with any screening abnormality underwent an echocardiogram for the assessment of structural heart disease. Murmurs were classified as physiological or pathological according to standard clinical criteria, and participants with murmurs were compared with a comparison group without murmurs. The primary outcome was echocardiogram-detected structural heart disease associated with SCD.

RESULTS

905 participants with a cardiac murmur (mean age 15.8; 58% male) and 4333 participants without a murmur (comparison group; mean age 15.8; 55% male) had an echocardiogram to detect structural heart disease. 743 (82%) murmurs were described as physiological and 162 (18%) as pathological. Twenty-five (2.8%) participants with murmurs and 61 (1.4%) participants without murmurs had structural heart disease. Three (0.3%) participants in the murmur group were diagnosed with hypertrophic cardiomyopathy (HCM) which was the only identified condition associated with SCD. Two participants with HCM had physiological murmurs, one had a pathological murmur, and all three had an abnormal ECG. The most common minor structural heart disease was bicuspid aortic valve in both the murmur (7; 0.8%) and comparison (20; 0.5%) groups. The positive predictive value of physiological versus pathological murmurs for identifying any structural heart disease was 2.4% versus 4.3% (p=0.21), respectively. The positive predictive value of having any murmur versus no murmur for identifying structural heart disease was 2.8% versus 1.4% (p=0.003), respectively.

CONCLUSIONS

In adolescents, the traditional classification of cardiac murmurs as 'physiologic' or 'pathologic' does not differentiate for structural heart disease that puts individuals at risk for SCD. We recommend ECG evaluation in all patients with a cardiac murmur found during preparticipation screening to increase detection of HCM.

Prevalence of Unexplained Left Ventricular Hypertrophy by Cardiac Magnetic Resonance Imaging in MESA

Background

Hypertrophic cardiomyopathy is defined as unexplained left ventricular (LV) hypertrophy (wall thickness ≥15 mm) and is prevalent in 0.2% of adults (1:500) in population‐based studies using echocardiography. Cardiac magnetic resonance imaging (MRI) allows for more accurate wall thickness measurement across the entire ventricle than echocardiography. The prevalence of unexplained LV hypertrophy by cardiac MRI is unknown. MESA (Multi‐Ethnic Study of Atherosclerosis) recruited individuals without overt cardiovascular disease 45 to 84 years of age.

Methods and Results

We studied 4972 individuals who underwent measurement of regional LV wall thickness by cardiac MRI as part of the MESA baseline exam. American Heart Association criteria were used to define LV segments. We excluded participants with hypertension, LV dilation (≥95% predicted end‐diastolic volume) or dysfunction (ejection fraction ≤50%), moderate‐to‐severe left‐sided valve lesions by cardiac MRI, severe aortic valve calcification by cardiac computed tomography (aortic valve Agatston calcium score >1200 in women or >2000 in men), obesity (body mass index >35 kg/m²), diabetes mellitus, and current smoking. Sixty‐seven participants (aged 64±10 years, 9% female) had unexplained LV hypertrophy (wall thickness ≥15 mm in at least 2 adjacent LV segments), representing 1.4% (1 in 74) participants, 2.6% of men and 0.2% of women. Prevalence was similar across categories of race/ethnicity. Hypertrophy was focal in 17 (25.4%), intermediate in 44 (65.7%), and diffuse in 5 (7.5%) participants.

Conclusions

The prevalence of unexplained LV hypertrophy in a population‐based cohort using cardiac MRI was 1.4%. This may have implications for the diagnosis of patients with hypertrophic cardiomyopathy and will require further study.

International recommendations for electrocardiographic interpretation in athletes

Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural, or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly over the last decade; pushed by a growing body of scientific data that both tests proposed criteria sets and establishes new evidence to guide refinements. On 26-27 February 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington, to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD.

Performance of the American Heart Association ( AHA ) 14-Point Evaluation Versus Electrocardiography for the Cardiovascular Screening of High School Athletes: A Prospective Study

Background

Preparticipation cardiovascular screening in athletes is fully endorsed by major medical societies, yet the most effective screening protocol remains debated. We prospectively compared the performance of the American Heart Association (AHA) 14‐point screening evaluation and a resting ECG for cardiovascular screening of high school athletes.

Methods and Results

Competitive athletes participating in organized high school or premier/select level sports underwent cardiovascular screening using the AHA 14‐point history and physical examination, and an ECG interpreted with the Seattle Criteria. A limited echocardiogram was performed for all screening abnormalities. The primary outcome measure was identification of a cardiovascular disorder associated with sudden cardiac death. From October 2014 to June 2017, 3620 high school athletes (median age, 16 years; range 13–19; 46.2% female; 78.6% white, 8.0% black) were screened. One or more positive responses to the AHA 14‐point questionnaire were present in 814 (22.5%) athletes. The most common history responses included chest pain (8.1%), family history of inheritable conditions (7.3%), and shortness of breath (6.4%). Abnormal physical examination was present in 356 (9.8%) athletes, and 103 (2.8%) athletes had an abnormal ECG. Sixteen (0.4%) athletes had conditions associated with sudden cardiac death. The sensitivity (18.8%), specificity (68.0%), and positive predictive value (0.3%) of the AHA 14‐point evaluation was substantially lower than the sensitivity (87.5%), specificity (97.5%), and positive predictive value (13.6%) of ECG.

Conclusions

The AHA 14‐point evaluation performs poorly compared with ECG for cardiovascular screening of high school athletes. The use of consensus‐derived history questionnaires as the primary tool for cardiovascular screening in athletes should be reevaluated.

See Editorial Maron et al

Relationship of bone mineral density with valvular and annular calcification in community-dwelling older people: The Cardiovascular Health Study

Associations between bone mineral density and aortic valvular, aortic annular, and mitral annular calcification were investigated in a cross-sectional analysis of a population-based cohort of 1497 older adults. Although there was no association between continuous bone mineral density and outcomes, a significant association between osteoporosis and aortic valvular calcification in men was found.

INTRODUCTION

The process of cardiac calcification bears a resemblance to skeletal bone metabolism and its regulation. Experimental studies suggest that bone mineral density (BMD) and valvular calcification may be reciprocally related, but epidemiologic data are sparse.

METHODS

We tested the hypothesis that BMD of the total hip and femoral neck measured by dual-energy X-ray absorptiometry (DXA) is inversely associated with prevalence of three echocardiographic measures of cardiac calcification in a cross-sectional analysis of 1497 older adults from the Cardiovascular Health Study. The adjusted association of BMD with aortic valve calcification (AVC), aortic annular calcification (AAC), and mitral annular calcification (MAC) was assessed with relative risk (RR) regression.

RESULTS

Mean (SD) age was 76.2 (4.8) years; 58% were women. Cardiac calcification was highly prevalent in women and men: AVC, 59.5 and 71.0%; AAC 45.1 and 46.7%; MAC 42.8 and 39.5%, respectively. After limited and full adjustment for potential confounders, no statistically significant associations were detected between continuous BMD at either site and the three measures of calcification. Assessment of WHO BMD categories revealed a significant association between osteoporosis at the total hip and AVC in men (adjusted RR compared with normal BMD = 1.24 (1.01-1.53)). In graded sensitivity analyses, there were apparent inverse associations between femoral neck BMD and AVC with stenosis in men, and femoral neck BMD and moderate/severe MAC in women, but these were not significant.

CONCLUSION

These findings support further investigation of the sex-specific relationships between low BMD and cardiac calcification, and whether processes linking the two could be targeted for therapeutic ends.

Association of Triglyceride-Related Genetic Variants With Mitral Annular Calcification

BACKGROUND

Mitral annular calcium (MAC), commonly identified by cardiac imaging, is associated with cardiovascular events and predisposes to the development of clinically important mitral valve regurgitation and mitral valve stenosis. However, its biological determinants remain largely unknown.

OBJECTIVES

The authors sought to evaluate whether a genetic predisposition to elevations in plasma lipids is associated with the presence of MAC.

METHODS

The authors used 3 separate Mendelian randomization techniques to evaluate the associations of lipid genetic risk scores (GRS) with MAC in 3 large patient cohorts: the Framingham Health Study, MESA (Multiethnic European Study of Atherosclerosis), and the AGE-RS (Age, Gene/Environment Susceptibility-Reykjavik Study). The authors provided cross-ethnicity replication in the MESA Hispanic-American participants.

RESULTS

MAC was present in 1,149 participants (20.4%). In pooled analyses across all 3 cohorts, a triglyceride GRS was significantly associated with the presence of MAC (odds ratio [OR] per triglyceride GRS unit: 1.73; 95% confidence interval [CI]: 1.24 to 2.41; p = 0.0013). Neither low- nor high-density lipoprotein cholesterol GRS was significantly associated with MAC. Results were consistent in cross-ethnicity analyses among the MESA Hispanic-Americans cohort (OR per triglyceride GRS unit: 2.04; 95% CI: 1.03 to 4.03; p = 0.04). In joint meta-analysis across all included cohorts, the triglyceride GRS was associated with MAC (OR per triglyceride GRS unit: 1.79; 95% CI: 1.32 to 2.41; p = 0.0001). The results were robust to several sensitivity analyses that limit both known and unknown forms of genetic pleiotropy.

CONCLUSIONS

Genetic predisposition to elevated triglyceride levels was associated with the presence of MAC, a risk factor for clinically significant mitral valve disease, suggesting a causal association. Whether reducing triglyceride levels can lower the incidence of clinically significant mitral valve disease requires further study.

International Recommendations for Electrocardiographic Interpretation in Athletes

Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural, or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly over the last decade; pushed by a growing body of scientific data that both tests proposed criteria sets and establishes new evidence to guide refinements. On February 26-27, 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington, to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD.

Cardiac Magnetic Resonance Imaging Versus Transthoracic Echocardiography for Prediction of Outcomes in Chronic Aortic or Mitral Regurgitation

In subjects with aortic regurgitation (AR) or mitral regurgitation (MR), transthoracic echocardiography (TTE) is recommended for surveillance. Few prospective studies have directly compared the ability of TTE and cardiac magnetic resonance (CMR) to predict clinical outcomes in AR and MR. We hypothesized that, given its higher reproducibility, CMR would predict the need for valve surgery or heart failure (HF) hospitalization better than TTE. Quantitative TTE and CMR were performed on the same day for 51 subjects: 29 with chronic AR and 22 with chronic, primary MR for quantification of valve regurgitation. Baseline measurements of valve regurgitation were compared to the combined primary end point of new HF and valve surgery using receiver operating characteristics, simple logistic regression, and Kaplan-Meier survival analyses. The primary end point occurred in 5 AR subjects (all surgery) and 8 MR subjects (7 surgery, 1 HF) after a mean follow-up of 4.4 ± 1.5 years. For AR, CMR-derived regurgitant volume >50 ml identified those at high risk with 50% undergoing valve surgery versus 0% for those with regurgitant volume ≤50 ml and was more strongly associated with outcomes than regurgitant volume by TTE (p <0.05). For MR, 6.8% of those with regurgitant volume by TTE ≤30 ml developed the primary end point versus 70% in those with regurgitant volume >30 ml. Regurgitant volume by CMR showed no significant separation of survival curves for MR. In conclusion, regurgitant volume by CMR was more predictive of outcomes than by TTE in subjects with AR. In MR, the 2 methods performed similarly.

International criteria for electrocardiographic interpretation in athletes: Consensus statement

Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly, advanced by a growing body of scientific data and investigations that both examine proposed criteria sets and establish new evidence to guide refinements. On 26-27 February 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington (USA), to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD.

Incidence and Etiology of Sudden Cardiac Arrest and Death in High School Athletes in the United States

OBJECTIVE

To determine the incidence and etiology of sudden cardiac arrest and death (SCA/D) in US high school athletes.

PATIENTS AND METHODS

A prospective media database of SCA/D was queried for cases aged 14 to 18 years from 7 states over 6 school years (September 1, 2007, to August 30, 2013). Event details were investigated to determine participation on a high school athletic team, sex, sport, and occurrence during school-sponsored activity or exertion. National sports participation numbers were used and a conversion factor was applied to account for multisport athletes. Autopsy reports were reviewed and cause of death was adjudicated by an expert panel.

RESULTS

A total of 16,390,409 million athlete-seasons representing 6,974,640 athlete-years (AY) were examined, encompassing 36% of the total US high school athlete population. A total of 104 cases of SCA/D were identified (35 SCA with survival and 69 sudden cardiac deaths [SCDs]). The rate of SCD was 1:101,082 AY and of SCA/D 1:67,064 AY. Eighty-eight percent (92) of events occurred in male athletes. The rate of SCA/D in male athletes was 1:44,832 AY and in female athletes 1:237,510 AY (incidence rate ratio, 5.3; 95% CI, 2.9-10.6; P<.001). Men's basketball was the highest risk sport with an SCA/D incidence of 1:37,087 AY followed by men's football at 1:86,494 AY. Men's basketball and football athletes accounted for 57% (39) of deaths. Eighty percent of SCDs (55 of 69) were exertional and 55% (38 of 69) occurred while playing for a school-sponsored team. Autopsy reports were obtained in 73% (50) of cases. The most common findings of autopsy were idiopathic left ventricular hypertrophy or possible cardiomyopathy (13 of 50 [26%]), autopsy-negative sudden unexplained death (9 of 50 [18%]), hypertrophic cardiomyopathy (7 of 50 [14%]), and myocarditis (7 of 50 [14%]).

CONCLUSION

The rate of SCA/D in male high school athletes was 1:44,832 AY, with almost half due to possible or confirmed cardiomyopathy disease. It is likely that many cases were not identified because of reliance on media reports, and these numbers represent a minimum estimate.

Electrocardiographic Screening in National Collegiate Athletic Association Athletes

The most effective protocol for cardiovascular screening of competitive athletes remains highly controversial. This study was a prospective, multicenter trial of cardiovascular screening at 35 National Collegiate Athletic Association institutions. Screening included a standardized history and physical examination (PE) as recommended by the American Heart Association and a 12-lead electrocardiogram (ECG) at rest. Centralized electrocardiographic interpretation was provided using the Seattle criteria. Athletes with screening abnormalities underwent additional evaluation directed by the host institution medical team. Primary outcomes included the proportion of total and false-positive screens; the sensitivity, specificity, and positive predictive value of history, PE, and ECG; and the prevalence of serious cardiovascular disorders associated with severe morbidity or sudden cardiac death. From August 2012 to June 2014, 5,258 athletes from 17 intercollegiate sports were screened: 55% men (mean age 20.1 years), 73% Caucasian, 16% African-American, and 11% other/mixed race. At least 1 positive cardiac symptom or family history response was reported by 1,750 athletes (33.3%). PE was abnormal in 108 athletes (2.1%), and electrocardiographic abnormalities were present in 192 athletes (3.7%). Thirteen athletes (0.25%) were identified with serious cardiac conditions including hypertrophic cardiomyopathy (1), large atrial septal defect with right ventricular dilation (1), and ventricular pre-excitation (11). The false-positive rate for history was 33.3%, PE 2.0%, and ECG 3.4%. The sensitivity/specificity/positive predictive value for history was 15.4%/66.9%/0.1%, PE 7.7%/98.2%/0.9%, and ECG 100%/96.6%/6.8%. In conclusion, electrocardiographic screening in National Collegiate Athletic Association athletes has a low false-positive rate and provides superior accuracy compared with a standardized history and PE to detect athletes with potentially dangerous cardiovascular conditions.

Traumatic Carotid Artery Dissection and Pseudoaneurysm Treated with Endovascular Coils and Stent

Purpose:

To report a case of post-traumatic internal carotid artery dissection and pseudoaneurysm formation at the C-1 level successfully treated by a percutaneous endovascular technique.

Methods and Results:

A 20-year-old female presented 72 hours after a motor vehicle accident with incomplete occulosympathetic paresis (Horner's syndrome), carotidynia, and left-sided weakness. Arteriography confirmed the diagnosis of carotid dissection and an associated 1.5-cm × 2.5-cm pseudoaneurysm at the C-1 level. Neuroradiologists embolized the pseudoaneurysm with Guglielmi detachable coils and controlled the dissection with placement of a Wallstent.

Conclusions:

This report illustrates successful percutaneous endovascular treatment of a carotid dissection and pseudoaneurysm near the base of the skull.

Incidence, Cause, and Comparative Frequency of Sudden Cardiac Death in National Collegiate Athletic Association Athletes: A Decade in Review

BACKGROUND

The incidence and cause of sudden cardiac death (SCD) in athletes is debated with hypertrophic cardiomyopathy often reported as the most common cause.

METHODS AND RESULTS

A database of all National Collegiate Athletic Association deaths (2003-2013) was developed. Additional information and autopsy reports were obtained when possible. Cause of death was adjudicated by an expert panel. There were 4 242 519 athlete-years (AY) and 514 total student athlete deaths. Accidents were the most common cause of death (257, 50%, 1:16 508 AY) followed by medical causes (147, 29%, 1:28 861 AY). The most common medical cause of death was SCD (79, 15%, 1:53 703 AY). Males were at higher risk than females 1:37 790 AY versus 1:121 593 AY (incidence rate ratio, 3.2; 95% confidence interval, 1.9-5.5; P<0.00001), and black athletes were at higher risk than white athletes 1:21491 AY versus 1:68 354 AY (incidence rate ratio, 3.2; 95% confidence interval, 1.9-5.2; P<0.00001). The incidence of SCD in Division 1 male basketball athletes was 1:5200 AY. The most common findings at autopsy were autopsy-negative sudden unexplained death in 16 (25%), and definitive evidence for hypertrophic cardiomyopathy was seen in 5 (8%). Media reports identified more deaths in higher divisions (87%, 61%, and 44%), whereas the percentages from the internal database did not vary (87%, 83%, and 89%). Insurance claims identified only 11% of SCDs.

CONCLUSIONS

The rate of SCD in National Collegiate Athletic Association athletes is high, with males, black athletes, and basketball players at substantially higher risk. The most common finding at autopsy is autopsy-negative sudden unexplained death. Media reports are more likely to capture high-profile deaths, and insurance claims are not a reliable method for case identification.

Association of low-density lipoprotein cholesterol-related genetic variants with aortic valve calcium and incident aortic stenosis

IMPORTANCE

Plasma low-density lipoprotein cholesterol (LDL-C) has been associated with aortic stenosis in observational studies; however, randomized trials with cholesterol-lowering therapies in individuals with established valve disease have failed to demonstrate reduced disease progression.

OBJECTIVE

To evaluate whether genetic data are consistent with an association between LDL-C, high-density lipoprotein cholesterol (HDL-C), or triglycerides (TG) and aortic valve disease.

DESIGN, SETTING, AND PARTICIPANTS

Using a Mendelian randomization study design, we evaluated whether weighted genetic risk scores (GRSs), a measure of the genetic predisposition to elevations in plasma lipids, constructed using single-nucleotide polymorphisms identified in genome-wide association studies for plasma lipids, were associated with aortic valve disease. We included community-based cohorts participating in the CHARGE consortium (n = 6942), including the Framingham Heart Study (cohort inception to last follow-up: 1971-2013; n = 1295), Multi-Ethnic Study of Atherosclerosis (2000-2012; n = 2527), Age Gene/Environment Study-Reykjavik (2000-2012; n = 3120), and the Malmö Diet and Cancer Study (MDCS, 1991-2010; n = 28,461).

MAIN OUTCOMES AND MEASURES

Aortic valve calcium quantified by computed tomography in CHARGE and incident aortic stenosis in the MDCS.

RESULTS

The prevalence of aortic valve calcium across the 3 CHARGE cohorts was 32% (n = 2245). In the MDCS, over a median follow-up time of 16.1 years, aortic stenosis developed in 17 per 1000 participants (n = 473) and aortic valve replacement for aortic stenosis occurred in 7 per 1000 (n = 205). Plasma LDL-C, but not HDL-C or TG, was significantly associated with incident aortic stenosis (hazard ratio [HR] per mmol/L, 1.28; 95% CI, 1.04-1.57; P = .02; aortic stenosis incidence: 1.3% and 2.4% in lowest and highest LDL-C quartiles, respectively). The LDL-C GRS, but not HDL-C or TG GRS, was significantly associated with presence of aortic valve calcium in CHARGE (odds ratio [OR] per GRS increment, 1.38; 95% CI, 1.09-1.74; P = .007) and with incident aortic stenosis in MDCS (HR per GRS increment, 2.78; 95% CI, 1.22-6.37; P = .02; aortic stenosis incidence: 1.9% and 2.6% in lowest and highest GRS quartiles, respectively). In sensitivity analyses excluding variants weakly associated with HDL-C or TG, the LDL-C GRS remained associated with aortic valve calcium (P = .03) and aortic stenosis (P = .009). In instrumental variable analysis, LDL-C was associated with an increase in the risk of incident aortic stenosis (HR per mmol/L, 1.51; 95% CI, 1.07-2.14; P = .02).

CONCLUSIONS AND RELEVANCE

Genetic predisposition to elevated LDL-C was associated with presence of aortic valve calcium and incidence of aortic stenosis, providing evidence supportive of a causal association between LDL-C and aortic valve disease. Whether earlier intervention to reduce LDL-C could prevent aortic valve disease merits further investigation.

Cardiovascular screening in adolescents and young adults: a prospective study comparing the Pre-participation Physical Evaluation Monograph 4th Edition and ECG

BACKGROUND

This study compares the accuracy of cardiovascular screening in active adolescents and young adults using a standardised history, physical examination and resting 12-lead ECG.

METHODS

Participants were prospectively screened using a standardised questionnaire based on the Pre-participation Physical Evaluation Monograph 4th Edition (PPE-4), physical examination and ECG interpreted using modern standards. Participants with abnormal findings had focused echocardiography and further evaluation. Primary outcomes included disorders associated with sudden cardiac arrest (SCA).

RESULTS

From September 2010 to July 2011, 1339 participants underwent screening: age 13-24 (mean 16) years, 49% male, 68% Caucasian, 17% African-American and 1071 (80%) participating in organised sports. Abnormal history responses were reported on 916 (68%) questionnaires. After physician review, 495/916 (54%) participants with positive questionnaires were thought to have non-cardiac symptoms and/or a benign family history and did not warrant additional evaluation. Physical examination was abnormal in 124 (9.3%) participants, and 72 (5.4%) had ECG abnormalities. Echocardiograms were performed in 586 (44%) participants for abnormal history (31%), physical examination (8%) or ECG (5%). Five participants (0.4%) were identified with a disorder associated with SCA, all with ECG-detected Wolff-Parkinson-White. The false-positive rates for history, physical examination and ECG were 31.3%, 9.3% and 5%, respectively.

CONCLUSIONS

A standardised history and physical examination using the PPE-4 yields a high false-positive rate in a young active population with limited sensitivity to identify those at risk for SCA. ECG screening has a low false-positive rate using modern interpretation standards and improves detection of primary electrical disease at risk of SCA.

Genetic associations with valvular calcification and aortic stenosis

BACKGROUND

Limited information is available regarding genetic contributions to valvular calcification, which is an important precursor of clinical valve disease.

METHODS

We determined genomewide associations with the presence of aortic-valve calcification (among 6942 participants) and mitral annular calcification (among 3795 participants), as detected by computed tomographic (CT) scanning; the study population for this analysis included persons of white European ancestry from three cohorts participating in the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium (discovery population). Findings were replicated in independent cohorts of persons with either CT-detected valvular calcification or clinical aortic stenosis.

RESULTS

One SNP in the lipoprotein(a) (LPA) locus (rs10455872) reached genomewide significance for the presence of aortic-valve calcification (odds ratio per allele, 2.05; P=9.0×10(-10)), a finding that was replicated in additional white European, African-American, and Hispanic-American cohorts (P<0.05 for all comparisons). Genetically determined Lp(a) levels, as predicted by LPA genotype, were also associated with aortic-valve calcification, supporting a causal role for Lp(a). In prospective analyses, LPA genotype was associated with incident aortic stenosis (hazard ratio per allele, 1.68; 95% confidence interval [CI], 1.32 to 2.15) and aortic-valve replacement (hazard ratio, 1.54; 95% CI, 1.05 to 2.27) in a large Swedish cohort; the association with incident aortic stenosis was also replicated in an independent Danish cohort. Two SNPs (rs17659543 and rs13415097) near the proinflammatory gene IL1F9 achieved genomewide significance for mitral annular calcification (P=1.5×10(-8) and P=1.8×10(-8), respectively), but the findings were not replicated consistently.

CONCLUSIONS

Genetic variation in the LPA locus, mediated by Lp(a) levels, is associated with aortic-valve calcification across multiple ethnic groups and with incident clinical aortic stenosis. (Funded by the National Heart, Lung, and Blood Institute and others.).

Aortic valve calcium independently predicts coronary and cardiovascular events in a primary prevention population

OBJECTIVES

This study sought to test whether aortic valve calcium (AVC) is independently associated with coronary and cardiovascular events in a primary-prevention population.

BACKGROUND

Aortic sclerosis is associated with increased cardiovascular morbidity and mortality among the elderly, but the mechanisms underlying this association remain controversial. Also, it is unknown whether this association extends to younger individuals.

METHODS

We performed a prospective analysis of 6,685 participants in MESA (Multi-Ethnic Study of Atherosclerosis). All subjects, ages 45 to 84 years and free of clinical cardiovascular disease at baseline, underwent computed tomography for AVC and coronary artery calcium scoring. The primary, pre-specified combined endpoint of cardiovascular events included myocardial infarctions, fatal and nonfatal strokes, resuscitated cardiac arrest, and cardiovascular death, whereas a secondary combined endpoint of coronary events excluded strokes. The association between AVC and clinical events was assessed using Cox proportional hazards regression with incremental adjustments for demographics, cardiovascular risk factors, inflammatory biomarkers, and subclinical coronary atherosclerosis.

RESULTS

Over a median follow-up of 5.8 years (interquartile range: 5.6 to 5.9 years), adjusting for demographics and cardiovascular risk factors, subjects with AVC (n = 894, 13.4%) had higher risks of cardiovascular (hazard ratio [HR]: 1.50; 95% confidence interval [CI]: 1.10 to 2.03) and coronary (HR: 1.72; 95% CI: 1.19 to 2.49) events compared with those without AVC. Adjustments for inflammatory biomarkers did not alter these associations, but adjustment for coronary artery calcium substantially attenuated both cardiovascular (HR: 1.32; 95% CI: 0.98 to 1.78) and coronary (HR: 1.41; 95% CI: 0.98 to 2.02) event risk. AVC remained predictive of cardiovascular mortality even after full adjustment (HR: 2.51; 95% CI: 1.22 to 5.21).

CONCLUSIONS

In this MESA cohort, free of clinical cardiovascular disease, AVC predicts cardiovascular and coronary event risk independent of traditional risk factors and inflammatory biomarkers, likely due to the strong correlation between AVC and subclinical atherosclerosis. The association of AVC with excess cardiovascular mortality beyond coronary atherosclerosis risk merits further investigation. (Multi-Ethnic Study of Atherosclerosis [MESA]; NCT00005487).

Electrocardiogram interpretation in the athlete

The sudden death of a young athlete is a devastating event that impacts the lay public and medical community and has attracted efforts to screen for underlying cardiovascular diseases associated with sudden death in this population. Electrocardiography (ECG) screening has been shown to increase the sensitivity of finding structural heart diseases in competitive athletes. Recent research in diverse populations of athletes has led to refinements in ECG-interpretation standards designed to improve its diagnostic accuracy. This review summarizes relevant information regarding cardiovascular screening and ECG interpretation in athletes.

Correlation of echocardiographic findings with cerebral infarction in elderly adults: the AGES-Reykjavik study

BACKGROUND AND PURPOSE

Chronic effects of hypertension may be observed in multiple end organs. Previous reports suggest that cardiovascular morphological features can mirror cerebral infarction. In this cross-sectional analysis of elderly subjects, we investigated the relationship of a comprehensive set of echocardiographic measures with cerebral infarction detected by MRI.

METHODS

We compared echocardiographically determined left ventricular (LV) mass, left atrial volume, aortic root diameter, mitral annular calcification, and measures of diastolic function with cerebral infarction determined by MRI using logistic regression in a random sample drawn from the Age Gene/Environment Susceptibility-Reykjavik Study cohort. The model was first adjusted for age and gender, and then for age, gender, and vascular risk factors.

RESULTS

Among 692 subjects aged 75 (standard deviation, 6) years, 28% had at least 1 cerebral infarct. When adjusted for age and gender, the presence of cerebral infarction was modestly related to LV mass (odds ratio [OR], 1.01; 95% confidence interval [CI], 1.00-1.02) and left atrial volume (OR, 1.03; 95% CI, 1.01-1.05), as well as the lowest quartile of early-to-late pulsed Doppler velocity ratio (early-to-late pulsed Doppler velocity ratio <0.75; OR, 1.87; 95% CI, 1.22-2.87). The latter relation remained significant after adjustment for vascular risk factors and LV ejection fraction (OR, 1.82; 95% CI, 1.16-2.86).

CONCLUSIONS

Of all echocardiographic parameters, LV filling abnormality as indicated by low early-to-late pulsed Doppler velocity ratio displayed the strongest association with cerebral infarction and this relationship was independent of vascular risk factors. This simple marker of cerebral infarction may be useful when evaluating older patients.

Incidence and progression of aortic valve calcium in the Multi-ethnic Study of Atherosclerosis (MESA)

Aortic valve calcium (AVC) is common among older adults and shares epidemiologic and histopathologic similarities to atherosclerosis. However, prospective studies have failed to identify meaningful risk associations with incident ("new") AVC or its progression. In the present study, AVC was quantified from serial computed tomographic images from 5,880 participants (aged 45 to 84 years) in the Multi-Ethnic Study of Atherosclerosis, using the Agatston method. Multivariate backward selection modeling was used to identify the risk factors for incident AVC and AVC progression. During a mean follow-up of 2.4 +/- 0.9 years, 210 subjects (4.1%) developed incident AVC. The incidence rate (mean 1.7%/year) increased significantly with age (p <0.001). The risk factors for incident AVC included age, male gender, body mass index, current smoking, and the use of lipid-lowering and antihypertensive medications. Among those with AVC at baseline, the median rate of AVC progression was 2 Agatston units/year (interquartile range -21 to 37). The baseline Agatston score was a strong, independent predictor of progression, especially among those with high calcium scores at baseline. In conclusion, in this ethnically diverse, preclinical cohort, the rate of incident AVC increased significantly with age. The incident AVC risk was associated with several traditional cardiovascular risk factors, specifically age, male gender, body mass index, current smoking, and the use of both antihypertensive and lipid-lowering medications. AVC progression risk was associated with male gender and the baseline Agatston score. Additional research is needed to determine whether age- and stage-specific mechanisms underlie the risk of AVC progression.

Age-modification of lipoprotein, lipid, and lipoprotein ratio-associated risk for coronary artery calcium (from the Multi-Ethnic Study of Atherosclerosis [MESA])

Although abnormal lipoproteins and lipoprotein ratios are powerful risk factors for clinical cardiovascular events, these associations are stronger in younger than in older subjects. Whether age modifies the relation of lipoproteins and lipoprotein ratios to the relative risk of subclinical cardiovascular disease (CVD), as assessed by coronary artery calcium (CAC) scores, has not been examined in a contemporary, multiethnic cohort. We performed multivariate relative risk regression analyses to determine the relative risks for associations of lipoproteins and lipoprotein ratios with prevalent CAC in participants in Multi-Ethnic Study of Atherosclerosis (MESA). The participants were community-dwelling adults aged 45 to 84 years without clinically apparent CVD at baseline. We excluded those taking lipid-lowering therapy (15%) and stratified the results by decades of age. A total of 5,092 participants met the inclusion criteria. In the fully adjusted models, per SD of low-density lipoprotein, the age-stratified, adjusted relative risk for CAC was 1.17 (95% confidence interval [CI] 1.07 to 1.28) for those aged 45 to 84 years but was 1.05 (95% CI 1.01 to 1.10) for those aged 75 to 84 years (p-interaction = 0.12). The relative risk per SD of total/high-density lipoprotein cholesterol ratio was 1.20 (95% CI 1.12 to 1.29) for those aged 45 to 54 years but only 1.04 (95% CI 1.00 to 1.09) for those aged 75 to 84 years (p-interaction <0.001). The lipoproteins levels and lipoprotein ratios were associated with increased relative risks for CAC across all age categories. However, these associations were markedly attenuated by age. In conclusion, abnormal lipoprotein levels in middle age are a powerful risk factor for early atherosclerosis, as manifested by prevalent CAC.

Ventilatory efficiency and resting hemodynamics in hypertrophic cardiomyopathy

PURPOSE

In patients with systolic heart failure, the ability of cardiopulmonary exercise testing (CPX) variables to reflect pathophysiology is well established. The relationship between CPX and pathophysiology has, however, not been thoroughly investigated in patients with nonobstructive hypertrophic cardiomyopathy (NHCM). The objective of this study was to assess the ability of CPX variables to reflect resting hemodynamics in patients with nonobstructive hypertrophic cardiomyopathy NHCM.

METHODS

We performed CPX and right heart catheterization on 83 subjects with NHCM (51 male/32 female, mean age = 38 +/- 10 yr, NYHA I-III mean = 1.7). Peak oxygen consumption ( O2) and minute ventilation/carbon dioxide ratio (V E/VCO2) at peak exercise were compared to resting hemodynamics including pulmonary artery systolic, diastolic and mean pressures (PASP, PADP and MPAP), and pulmonary capillary wedge pressure (PCWP).

RESULTS

Elevations in PCWP (> or = 15 mm Hg), PASP (> or =30 and > or = 40 mm Hg), PADP (> 15 mm Hg) and MPAP (> or = 20 mm Hg) were detected in 22, 33, 10, and 23% of subjects, respectively. Peak V E/VCO2 (positive correlation) and peak VO2 (negative correlation) correlated modestly with all pressure measurements (r = 0.33-0.51, P < 0.01 for all measurements). By receiver operating curve analysis, a V E/VCO2 >35.5 exhibited the best diagnostic accuracy with a curve areas of 0.81 for PAP > or = 30 mm Hg (sensitivity/specificity = 86%/67%), 0.87 for PAP > or = 40 mm Hg (77%/100%), 0.86 for MPAP > 20 mm Hg (83%/79%), and 0.84 for PCWP > or = 15 mm Hg (80%/76%).

CONCLUSIONS

CPX can accurately identify abnormal resting hemodynamics in patients with NHCM. Further testing of this modality in other forms of diastolic dysfunction may be warranted.

Interaction of age with lipoproteins as predictors of aortic valve calcification in the multi-ethnic study of atherosclerosis

BACKGROUND

Previous epidemiologic studies have shown that low-density lipoprotein is an independent risk factor for prevalent aortic valve calcification (AVC); however, to our knowledge, the interactions between plasma lipoprotein concentrations and age on the relative risks (RRs) for AVC prevalence and severity have not been examined in a large, racially and ethnically diverse cohort.

METHODS

Using stepwise RR regression, the relationships of baseline fasting lipid levels and lipoprotein levels to baseline prevalence and severity of AVC were determined in 5801 non-statin-using participants in the Multi-Ethnic Study of Atherosclerosis (MESA).

RESULTS

In age-stratified, adjusted analyses, the low-density lipoprotein-associated RRs (95% confidence intervals) for prevalent AVC were higher for younger compared with older participants (age 45-54 years, 1.69 [1.19-2.39]; age 55-64 years, 1.48 [1.24-1.76]; age 65-74 years, 1.09 [0.95-1.25]; and age 75-84 years, 1.16 [0.99-1.36]; P interaction = .04]. There was a similar, significant interaction of age with total cholesterol-associated RR for prevalent AVC (P interaction = .04). In contrast, total- to high-density lipoprotein cholesterol ratio RRs were similar across all age strata (P interaction = .68). At multivariate analyses, no lipoprotein parameter was associated with AVC severity.

CONCLUSIONS

In this racially and ethnically diverse, preclinical cohort, low-density lipoprotein was a risk factor for AVC only in participants younger than 65 years, whereas the total cholesterol/high-density lipoprotein cholesterol ratio was associated with a modest increased risk of AVC across all ages. These findings may have important implications for the efficacy of and targets for dyslipidemia therapies in calcific aortic valve disease.

Thromboembolic complications after inferior petrosal sinus sampling in patients with cushing's syndrome

OBJECTIVE

To heighten the awareness of treating physicians of the potential for serious and fatal thromboembolic complications after inferior petrosal sinus sampling in patients with Cushing's syndrome.

METHODS

We retrospectively reviewed inpatient and outpatient medical records for a 12-year period to identify patients with Cushing's syndrome who had thromboembolic complications after inferior petrosal sinus sampling at a single institution. Case reports of affected patients are presented.

RESULTS

Of 34 patients with corticotropin-dependent Cushing's syndrome who underwent inferior petrosal sinus sampling, 2 had deep venous thrombosis. One of these patients succumbed to pulmonary thromboembolism.

CONCLUSION

Serious and potentially fatal thromboembolic disorders may complicate inferior petrosal sinus sampling. Prospective studies should be undertaken to determine the true incidence of deep venous thrombosis after this procedure in patients with Cushing's syndrome.

Prevention of complications resulting from endovascular carotid sacrifice: a retrospective assessment

OBJECTIVE

To determine the protective effects of various periprocedural interventions in the prevention of cerebral ischemia as a complication of endovascular carotid sacrifice (ECS).

METHODS

Thirty-two cases of ECS performed at our institution, between October 1987 and July 1998, were reviewed. Fifteen patients underwent superficial temporal artery-to-middle cerebral artery bypass surgery. In 21 patients, the carotid artery was occluded proximal to the target lesion; and in 11 patients, a lesion trapping procedure was performed. Six patients were prophylactically anticoagulated, 14 received antiplatelet agents prophylactically, and 12 received no pharmacoprophylaxis.

RESULTS

Among the six patients who were anticoagulated, there were no embolic events. Embolic events affected 4 of 14 patients receiving prophylactic antiplatelet agents, 2 of 12 patients receiving no pharmacoprophylaxis, 1 of 11 patients who underwent a trapping procedure, and 5 of 21 patients whose carotid artery was occluded proximal to the target lesion. Postocclusion cerebral ischemia developed in 7 of 15 patients who underwent bypass surgery, and in 1 of the remaining 17.

CONCLUSION

Superficial temporal artery-to-middle cerebral artery bypass did not protect against postocclusion cerebral ischemia after ECS in this series (P = 0.01). Although the small number of patients studied precludes statistical validity (P = 0.29), the trends suggest that antiplatelet agents provide no protection against postocclusion cerebral emboli after ECS. Prophylactic anticoagulation (P = 0.32) and lesion trapping (P = 0.12) may reduce the frequency of postocclusion embolic events after ECS; however, because of the small number of patients, statistical significance could not be demonstrated.

Diurnal variations in the mood and performance of highly practised young women living under strictly controlled conditions

The diurnal variation in a range of psychological functions and core body temperature were investigated in a series of studies involving a total of 24 highly practised young women who lived in a controlled environment and on a strictly regimented 24-hour routine for 6 or 7 days. Ten participants were exposed to the natural light/dark cycle (L/Dc) through windows, whereas the 14 remaining participants saw no daylight, but all had access to normal clock time. A battery of mood and performance tests was completed every 2 hours whilst awake (08:00-00:00), resulting in nine equally spaced measures per waking day. Average time of day (ToD) functions were calculated from the last 5 or 6 days spent in the controlled environment. Significant ToD effects were found for many of the variables taken although the nature of these effects differed across measures, with a 'post-lunch dip' being observed at 16:00 in some variables. Analysis of the standardized data established that all variables presented reliably different ToD functions to core body temperature, whilst factor analyses indicated possible relationships between the variables. It was concluded that those variables that exhibited diurnal variation showed trends that did not parallel those in core body temperature.

Cryptosporidium andersoni n. sp. (Apicomplexa: Cryptosporiidae) from cattle, Bos taurus

A new species of Cryptosporidium is described from the feces of domestic cattle, Bos taurus. Oocysts are structurally similar to those of Cryptosporidium muris described from mice but are larger than those of Cryptosporidium parvum. Oocysts of the new species are ellipsoidal, lack sporocysts, and measure 7.4 x 5.5 microm (range, 6.0-8.1 by 5.0-6.5 microm). The length to width ratio is 1.35 (range, 1.07-1.50). The colorless oocyst wall is < 1 microm thick, lacks a micropyle, and possesses a longitudinal suture at one pole. A polar granule is absent, whereas an oocyst residuum is present. Oocysts were passed fully sporulated and are not infectious to outbred, inbred immunocompetent or immunodeficient mice, chickens or goats. Recent molecular analyses of the rDNA 18S and ITS1 regions and heat-shock protein 70 (HSP-70) genes demonstrate this species to be distinct from C. muris infecting rodents. Based on transmission studies and molecular data, we consider the large form of Cryptosporidium infecting the abomasum of cattle to be a new species and have proposed the name Cryptosporidium andersoni n. sp. for this parasite.

Diurnal trends in mood and performance do not all parallel alertness

OBJECTIVES

This study examined the hypothesis that alertness can be used to predict time-of-day effects on performance.

METHODS

For 6 or 7 days the volunteers (24, highly practiced young women) were required to retire to bed at 0000 and were awakened at 0800. A battery of mood and performance tests was completed every 2 hours while the women were awake; the result was 9 equally spaced measures per day. Measures of mood, serial reaction time, and memory scanning were recorded. Rectal temperature was recorded continuously.

RESULTS

After omitting the data from the first day to avoid any carry-over from the "first-night" effect on sleep, average time-of-day functions were calculated for each subject, for each variable, and were then z-transformed. Cross-correlations between the pooled time-of-day trends indicated that, while alertness was a reasonably good "predictor" of the simple perceptual-motor speed measures, it fared less well for some of the other measures. Two-way analyses of variance indicated that the time-of-day trend for all measures differed from that for alertness, although the magnitude of this difference varied substantially and, for some measures, was very largely due to the last reading of the day (0000).

CONCLUSION

It is clear from these results that, while alertness may successfully "predict" variations in some measures of performance capability, and especially those of simple perceptual motor speed, care should be exercised in extrapolating to other performance measures.

Time of day effects in, and the relationship between, sleep quality and movement

The study aimed to measure the effects of a 27-h 'day' sleep-wake regime on actigraphic and subjective sleep variables, and to examine the relationships between these variables. Nine subjects spent 30 days and nights in the laboratory. After sleeping 8 h for each of 8 nights, the subjects had an imposed 27-h 'day', for 18 'days', remaining in bed for 9 h on each sleep period. Sleep periods therefore started 3 h later each day, although subjects' circadian rhythms stayed entrained to 24 h, because subjects were not isolated from the natural light-dark cycle. Time asleep, subjective sleep efficiency and subjective sleep quality, but not movement during sleep, were found to be significantly affected by time of going to bed. There were significant decreases in movement during recovery sleeps following each of two episodes of 26 h sleep deprivation. Over the study there were significant within-subject correlations between subjective sleep quality and subjective sleep efficiency (rav = 0.65), movement during sleep and subjective sleep efficiency (rav = -0.48), and movement during sleep and subjective sleep quality (rav = -0.26). We conclude that sleep movement, despite its low within- and between-subjects variability, is nevertheless a statistically reliable, but weak, indicator of subjective sleep efficiency and quality.

Histologic and morphologic comparison of experimental aneurysms with human intracranial aneurysms

PURPOSE

Vein pouch aneurysms are the most commonly created experimental lesions in neuroendovascular research. We sought to determine whether an experimental aneurysm that is derived from a pancreatic elastase-digested arterial sac (EDASA) models the histology and morphology of human cerebral aneurysms more accurately than the vein pouch aneurysm does.

METHODS

EDASAs were created in the common carotid arteries of four rabbits, and vein pouch aneurysms were created in the common carotid arteries of four pigs. Five recently ruptured human cerebral aneurysms were obtained at autopsy. Identical histologic preparations were made for all specimens, and a vascular pathologist performed blinded histologic analyses. Morphologic dimensions were measured with a micrometer at 40-fold magnification.

RESULTS

In each human cerebral aneurysm, there was complete absence of internal elastic lamina and tunica media, and none showed evidence of mural inflammation or neointimal proliferation. Average wall thickness was 51 microm. All vein pouch aneurysms had a well-developed internal elastic lamina and tunica media, and all exhibited profound inflammation and neointimal proliferation. Average wall thickness was 290 microm. EDASAs were devoid of internal elastic lamina, their tunica medias were mildly atrophic, and the sac walls contained only mild inflammation and neointimal proliferation. Average wall thickness was 46 microm.

CONCLUSIONS

EDASAs model the morphologic and histologic characteristics of human cerebral aneurysms more accurately than vein pouch aneurysms do.

Transvenous embolization as the primary therapy for arteriovenous fistulas of the lateral and sigmoid sinuses

PURPOSE

We report on the evolution in one institution from transarterial embolization for the treatment of dural arteriovenous fistulas of the lateral and sigmoid sinuses to the safer and more durable technique of transvenous endovascular therapy for the majority of these lesions.

METHODS

Arterial, venous, and combined embolizations were performed for 24 fistulas of the lateral and sigmoid sinuses between August 1991 and December 1996. The patients were followed up clinically for 2 to 63 months, with a mean follow-up period of 30 months.

RESULTS

Nine patients had arterial embolization without transvenous treatment: five of the nine had angiographic and clinical obliteration of their fistulas; two of the nine, with unusual lesions, required surgery; and the remaining two had recurrences and were not retreated. Seven patients had both arterial embolization and coil embolization (packing) of the dural sinuses, four after arterial embolization had failed to cure the lesions; in all seven, the fistulas were obliterated angiographically and clinically. Eight patients had only transvenous coil embolization of the dural sinuses; all eight were cured. One patient had minimal arterial embolization during the primary venous embolization procedure. Complications occurred in two patients, both related to arterial embolization with ethanol.

CONCLUSION

Our experience suggests that arterial embolization of dural arteriovenous fistulas of the lateral and sigmoid sinuses is associated with a low cure rate and high rate of recurrence, whereas transvenous endovascular packing of the involved segment of the sinus results in a high cure rate that obviates arterial embolization or surgical excision in most cases.