Agmon, Yoram

Abstract While atherosclerosis has been suggested as a risk factor for VTE, previously identified mechanisms for atherosclerosis and VTE differ dramatically. Objectives: To compare (a) VTE-free survival and (b) observed vs. expected number of VTE events, among adult patients with and without aortic atherosclerosis. Design/Setting: Population-based prospective cohort study in Olmsted County, MN. Patients: Age- and sex-stratified random sample of the adult (≥45 years old) Olmsted County population identified over the three-year period, 1993–1995 (n=573), performed as part of the Stroke Prevention: Assessment of Risk in the Community (SPARC) study. Measurements: The SPARC study included a baseline clinical evaluation (interviews, review of medical records), blood pressure measurements, blood sampling, and transesophageal echocardiography (TEE). The Risk Factors for VTE in the Community study identified all incident VTE among Olmsted County residents over the 32-year period, 1966–1997, from which expected VTE events by age and sex were calculated. Results: Over 2830 person-years of follow-up, 12 SPARC patients developed VTE (7 idiopathic). The 4-year VTE-free survival was 99% and 98% for those with and those without any TEE-detected aortic atherosclerosis. Adjusting for age in a Cox proportional hazards model, lack of aortic atherosclerosis was significantly associated with subsequent VTE (p=0.01). Among the 276 patients without atherosclerosis observed for 1423 person-years, 7 VTE were observed compared to 2.6 expected (RR=2.7, 95%CI: 1.1, 5.6). Among the 291 patients with atherosclerosis (plaque ≥2mm), 4 VTE were observed compared to 5.8 expected (RR=0.7, 95%CI: 0.2, 1.8). Conclusions: Atherosclerosis is not a risk factor for incident VTE.

Background —Atrial septal aneurysm (ASA) is a putative risk factor for cardioembolism. However, the frequency of ASA in the general population has not been adequately determined. Therefore, the frequency in patients with cerebral ischemic events, compared with the frequency in the general population, is poorly defined. We sought to determine the frequency of ASA in the general population and to compare the frequency of ASA in patients with cerebral ischemic events with the frequency in the general population. Methods and Results —The frequency of ASA in the population was determined in 363 subjects, a sample of the participants in the Stroke Prevention: Assessment of Risk in a Community study (control subjects), and was compared with the frequency in 355 age- and sex-matched patients undergoing transesophageal echocardiography in search of a cardiac source of embolism after a focal cerebral ischemic event. The proportion with ASA was 7.9% in patients versus 2.2% in control subjects ( P =0.002; odds ratio of ASA, 3.65; 95% CI, 1.64 to 8.13, in patients versus control subjects). Patent foramen ovale (PFO) was detected with contrast injections in 56% of subjects with ASA. The presence of ASA predicted the presence of PFO (odds ratio of PFO, 4.57; 95% CI, 2.18 to 9.57, in subjects with versus those without ASA). In 86% of subjects with ASA and cerebral ischemia, transesophageal echocardiography did not detect an alternative source of cardioembolism other than an associated PFO. Conclusions —The prevalence of ASA based on this population-based study is 2.2%. The frequency of ASA is relatively higher in patients evaluated with transesophageal echocardiography after a cerebral ischemic event. ASA is frequently associated with PFO, suggesting paradoxical embolism as a mechanism of cardioembolism. In patients with cerebral ischemia and ASA, ASA (with or without PFO) commonly is the only potential cardioembolic source detected with transesophageal echocardiography.

Background —Atherosclerosis of the thoracic aorta is associated with stroke. The association between hypertension, a major risk factor for stroke, and aortic atherosclerosis has not been determined in the general population. Methods and Results —Transesophageal echocardiography was performed in 581 subjects, a random sample of the Olmsted County (Minnesota) population aged ≥45 years participating in the Stroke Prevention: Assessment of Risk in a Community (SPARC) study. Blood pressure was assessed by multiple office measurements and 24-hour ambulatory blood pressure monitoring. The association between blood pressure variables and aortic atherosclerosis was evaluated by multiple logistic regression, adjusting for other associated variables. Among subjects with atherosclerosis, blood pressure variables associated with complex aortic atherosclerosis (protruding plaques ≥4 mm thick, mobile debris, or ulceration) were determined. Age and smoking history were independently associated with aortic atherosclerosis of any degree ( P ≤0.001) and with complex atherosclerosis ( P =0.002), whereas sex, diabetes mellitus, and body mass index were not. Multiple systolic and pulse pressure variables (office and ambulatory), but none of the diastolic blood pressure variables, were associated with atherosclerosis and complex atherosclerosis, adjusting for age and smoking. Among subjects with atherosclerosis, the odds of complex atherosclerosis increased as ambulatory out-of-bed systolic blood pressure increased (odds ratio 1.43 per 10 mm Hg increase, 95% CI 1.10 to 1.87) and with hypertension treatment, adjusting for age and smoking history. Conclusions —High blood pressure is independently associated with aortic atherosclerosis. Among subjects with atherosclerosis, high blood pressure is associated with complex atherosclerosis.

Background — Left atrial (LA) thrombus is infrequently detected in the presence of sinus rhythm (SR) and, in these cases, is usually associated with additional cardiac pathologies. We sought to determine the clinical and echocardiographic characteristics of patients with LA thrombus and SR to define a high-risk group of patients prone to this uncommon clinical presentation. Methods and Results — The institution’s echocardiographic laboratory database was searched to identify patients with LA thrombus, diagnosed by transesophageal echocardiography (TEE), who were in SR during the TEE examination. Of 20 643 consecutive TEE examinations performed during an 11-year period, LA thrombus was detected in 314 patients in 380 TEE examinations. Of these, SR was present in 20 patients (age 69±13 years; 40% men) in 23 examinations (0.1% of all TEE examinations; 6.1% of TEE examinations with LA thrombus). High-risk structural heart disease (severe left ventricular dysfunction or significant left-sided valve disease [predominantly mitral valve disease]), previous documented episodes of atrial fibrillation, or both (structural heart disease and previous atrial fibrillation) were present in 10, 4, and 5 of the 20 patients, respectively. Only 1 patient with LA thrombus and SR did not have high-risk features. Conclusions — LA thrombus is very infrequently detected in the presence of SR. Patients with LA thrombus and SR constitute a high-risk group characterized by specific structural cardiac abnormalities or previous atrial fibrillation, abnormalities that are potentially detectable before TEE.