[1] BOSTON UNIV, BOSTON CITY HOSP, SCH MED, CARDIOL SECT, BOSTON, MA 02118 USA
[2] NHLBI, BETHESDA, MD 20892 USA
[3] BOSTON UNIV, DEPT MATH, BOSTON, MA 02215 USA
[4] BOSTON UNIV, SCH MED, DEPT PREVENT MED, BOSTON, MA 02118 USA
[5] BOSTON UNIV, SCH MED, DEPT NEUROL, BOSTON, MA 02118 USA
[6] BETH ISRAEL HOSP, DIV CARDIOL, BOSTON, MA USA
[7] BETH ISRAEL HOSP, DIV CLIN EPIDEMIOL, BOSTON, MA USA