[1] VET ADM MED CTR JAMAICA PLAIN, BOSTON, MA 02130 USA
[2] HARVARD UNIV, SCH MED, DEPT MED, DIV CARDIOVASC, BOSTON, MA 02115 USA
[3] TUFTS UNIV, SCH MED, BOSTON, MA 02111 USA
[4] BETH ISRAEL HOSP, CHARLES A DANA RES INST, BOSTON, MA 02215 USA
[5] BETH ISRAEL HOSP, THORNDIKE LAB, BOSTON, MA 02215 USA