Teresa S Tsang

Increased Left Atrial Volume Index: Potent Biomarker for First-Ever Ischemic Stroke

OBJECTIVEnTo establish the incidence and correlation of increased left atrial volume index (LAVI) in patients with first-ever ischemic stroke.nnnPARTICIPANTS AND METHODSnUsing our institutions epidemiological database, we defined a cohort of 432 patients (cases) who underwent transthoracic echocardiography within 60 days of first ischemic stroke between January 1, 1985, and December 31, 1994. Left atrial volume was measured with the biplane area-length method, indexed to body surface area (LAVI, expressed as mL/m(2)). The control group consisted of 416 community residents who underwent transthoracic echocardiography as participants in a stroke risk factor study. Increased LAVI was defined as 28 mL/m(2) or higher. Survival in patients was compared with expected survival among white Minnesotans and was further modeled as a function of age, sex, LAVI, and clinical risk factors.nnnRESULTSnAmong the included 306 patients, 230 (75%) had increased LAVI (mean+/-SD, 49+/-21 mL/m(2)). Patients with increased LAVI were older than those with normal LAVI (mean+/-SD age, 76+/-11 vs 71+/-13 years; P=.003) and had more cardiovascular risk factors (mean+/-SD number, 1.8+/-0.07 vs 1.3+/-0.89; P<.001). Mean LAVI was higher in cases than in age- and sex-matched controls (P<.001). At 5-year follow-up, cases showed excess mortality compared with age-matched controls (P=.001). After variables were adjusted for age, sex, and clinical risk factors, LAVI was independently associated with mortality.nnnCONCLUSIONnA useful index for prediction of adverse cardiovascular events, LAVI might also predict first ischemic stroke and subsequent mortality.

Relation of Dyspnea in Patients Unable to Perform Exercise Stress Testing to Outcome and Myocardial Ischemia

Limited information exists regarding the significance of dyspnea in patients who are unable to exercise and the contribution of myocardial ischemia to this symptom. To assess this, we evaluated results of dobutamine stress echocardiography (DSE) and long-term outcome of patients with dyspnea referred for DSE. We studied 6,376 consecutive patients who were unable to perform an exercise test and were referred for DSE. Patients were classified according to presenting symptoms and followed for 5.5 +/- 2.8 years. End points were cardiac ischemic events (myocardial infarction or revascularization), hospitalization for heart failure (HF), and death. Dobutamine stress echocardiogram was positive for ischemia in 19% of patients with dyspnea versus 24% (p = 0.002) of those with typical angina and 17% (p = 0.2) of asymptomatic patients. In multivariate analysis, risk of death was increased in dyspneic patients versus asymptomatic patients (hazard ratio [HR] 1.14, p = 0.02) and patients with chest pain (HR 1.20, p <0.001). Hospitalization for HF occurred more often in patients with dyspnea (HR 1.26, p = 0.05 vs asymptomatic; HR 1.24, p = 0.06 vs chest pain), especially in the subset without previous HF (HR 1.45, p = 0.006 vs chest pain). Risk of cardiac ischemic events in patients with dyspnea was similar versus asymptomatic patients (HR 0.92, p = 0.39) and decreased versus patients with chest pain (HR 0.70, p <0.001). In conclusion, in patients referred for DSE, dyspnea was associated with a poor outcome. This increased hazard seems not to be linked to myocardial ischemia, but instead to HF and death.