title: Reduced microvascular and myocardial damage in patients with acute myocardial infarction and preinfarction angina.
abstract: BACKGROUND
  After acute myocardial infarction, the presence of ischemic preconditioning as a result of preinfarction angina has a protective role, limiting necrosis extent and guaranteeing greater myocardial functional recovery. The relationship between preinfarction angina, microvascular reflow, and myocardial function is poorly known. We hypothesized that after acute myocardial infarction patients with preinfarction angina have both microvascular integrity and myocardial function preservation.
  
  
  RESULTS
  In 51 patients with a first acute myocardial infarction, we noninvasively assessed microvascular perfusion and coronary flow reserve with intravenous myocardial contrast echocardiography and investigated myocardial contractile recovery with low-dose dobutamine and 90-day follow-up echocardiography. Typical angina was present in 25 patients and absent in 26 patients during the 7 days preceding the myocardial infarction. Compared with those patients without preinfarction angina, patients with preinfarction angina showed a greater microvascular reflow extent and coronary flow reserve (respectively, 25.2% +/- 22.8% vs 48.3% +/- 23.3%, P <.05, and 3.44 +/- 0.75 vs 1.95 +/- 0.67, P <.0001), a better regional myocardial function, as expressed with wall motion score index in the risk area at dobutamine (1.67 +/- 0.61 vs 2.10 +/- 0.43, P <.005) and at follow-up (1.72 +/- 0.56 vs 2.22 +/- 0.40, P <.0001) echocardiogram, despite being similar in the first echocardiogram (2.60 +/- 0.28 vs 2.63 +/- 0.28, P = not significant), and significantly less pronounced left ventricular dilation at follow-up.
  
  
  CONCLUSIONS
  Presence of preinfarction angina, because of the preconditioning effect, reduces myocardial damage and favors myocardial viability, limiting left ventricular remodeling. This beneficial effect seems to be at least partly mediated by the more preserved microvascular integrity and functional vasodilation after acute myocardial infarction.
authors.affiliation: Department of Cardiovascular and Neurological Sciences, University of Cagliari, Cagliari, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Colonna
authors.forename: Christian
authors.initials: C
authors.lastname: Cadeddu
authors.forename: Roberta
authors.initials: R
authors.lastname: Montisci
authors.forename: Massimo
authors.initials: M
authors.lastname: Ruscazio
authors.forename: Abdel Hakem
authors.initials: AH
authors.lastname: Selem
authors.forename: Lijun
authors.initials: L
authors.lastname: Chen
authors.forename: Enrico
authors.initials: E
authors.lastname: Onnis
authors.forename: Luigi
authors.initials: L
authors.lastname: Meloni
authors.forename: Sabino
authors.initials: S
authors.lastname: Iliceto
mesh_terms: D000789:Angina, Unstable / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015906:Angioplasty, Balloon, Coronary; D003326:Coronary Circulation / Q000502:physiology*; D004452:Echocardiography; D025401:Echocardiography, Stress; D005260:Female; D006801:Humans; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy; D015588:Observer Variation; D011446:Prospective Studies