Giovanni Minardi

Prognostic value of dobutamine-atropine stress echocardiography early after acute myocardial infarction

OBJECTIVESnThe aim of this multicenter, multinational, prospective, observational study was to assess the relative value of myocardial viability and induced ischemia early after uncomplicated myocardial infarction.nnnBACKGROUNDnDobutamine-atropine stress echocardiography allows evaluation of rest function (at baseline), myocardial viability (at low dose) and residual ischemia (peak dose, up to 40 micrograms with atropine up to 1 mg) in one test.nnnMETHODSnDobutamine-atropine stress echocardiography was performed 12 +/- 5 days (mean +/- SD) after a first uncomplicated acute myocardial infarction in 778 patients (677 men; mean age 58 +/- 10 years) with technically satisfactory rest echocardiographic study results. Patients were followed-up for 9 +/- 7 months.nnnRESULTSnDobutamine-atropine stress echocardiographic findings were positive for myocardial ischemia in 436 of patients (56%) and negative in 342 (44%). During follow-up, there were 14 cardiac-related deaths (1.8% of the total cohort), 24 (2.9%) nonfatal myocardial infarctions and 63 (8%) hospital readmissions for unstable angina. One hundred seventy-four patients (22%) underwent coronary revascularization (bypass surgery or coronary angioplasty). Spontaneous events occurred in 61 of 436 patients with positive and 40 of 342 patients with negative findings on dobutamine-atropine stress echocardiography (14% vs. 12%, p = 0.3). When only spontaneously occurring events were considered, the most important predictor was myocardial viability (chi-square 9.7). Using the Cox proportional hazards model, only the presence of myocardial viability (hazard ratio [HR] 2.0, p < 0.002) and age (HR 1.03, p < 0.001) were predictive of spontaneously occurring events. When only hard cardiac events were considered, age was the strongest predictor (chi-square 3.6, p = 0.056), followed by wall motion score index (WMSI) at peak dose (chi-square 3.3, p = 0.06) and remote ischemia (chi-square 2.25, p = 0.1). When cardiac death was considered, WMSI at peak dose was the best predictor (HR 9.2, p < 0.0001).nnnCONCLUSIONSnDuring dobutamine stress, echocardiographic recognition of myocardial viability is more prognostically important than echocardiographic recognition of myocardial ischemia for predicting unstable angina, whereas WMSI at peak stress was the best predictor of cardiac-related death. Different events can be recognized with different efficiency by various stress echocardiographic variables.

Prognostic value of dipyridamole echocardiography early after uncomplicated myocardial infarction: A large-scale, multicenter trial

PURPOSEnTo determine the prognostic capability of the dipyridamole echocardiography test (DET) early after an acute myocardial infarction.nnnPATIENTS AND METHODSnOn the basis of 11 different echocardiographic laboratories, all with established experience in stress echocardiography and fulfilling quality-control requirements for stress echocardiographic readings, 925 patients were evaluated after a mean of 10 days from an acute myocardial infarction and followed up for a mean of 14 months.nnnRESULTSnDuring the follow-up, there were 34 deaths and 37 nonfatal myocardial infarctions; 104 patients developed class III or IV angina and 149 had coronary revascularization procedures (bypass or angioplasty). Considering all spontaneous events (angina, reinfarction, and death), the most important univariate predictor was the presence of an inducible wall motion abnormality after dipyridamole administration (chi 2 = 45.8). With a Cox analysis, echocardiographic positivity, age, and male gender were found to have an independent and additive value. Considering survival (and, therefore, death as the only event), age was the most meaningful parameter, followed by the wall motion score index during dipyridamole administration (chi 2 = 12.1). Among other parameters, the resting wall motion score index was a significant predictor of death. In a multivariate analysis, the prognostic contributions of age (relative risk estimate = 1.08) and wall motion score index during dipyridamole administration (relative risk estimate = 4.1) were independent and additive. In particular, considering death only, the event rate was 2% in patients with negative DET results, 4% in patients with positive high-dose DET results, and 7% in patients with positive low-dose DET results.nnnCONCLUSIONSnDET is feasible and safe early after uncomplicated myocardial infarction and allows effective risk stratification on the basis of the presence, severity, extent, and timing of the induced dyssynergy.

Prognostic Value of Myocardial Viability in Medically Treated Patients With Global Left Ventricular Dysfunction Early After an Acute Uncomplicated Myocardial Infarction A Dobutamine Stress Echocardiographic Study

BACKGROUNDnResidual viable myocardium identified by dobutamine stress after myocardial infarction may act as an unstable substrate for further events such as subsequent angina and reinfarction. However, in patients with severe global left ventricular dysfunction, viability might be protective rather than detrimental. The aim of this study was to assess the impact on survival of echocardiographically detected viability in medically treated patients with global left ventricular dysfunction evaluated after acute uncomplicated myocardial infarction.nnnMETHODS AND RESULTSnThe data bank of the large-scale, prospective, multicenter, observational Echo Dobutamine International Cooperative (EDIC) study was interrogated to select 314 medically treated patients (271 men; age, 58+/-9 years) who underwent low-dose (</=10 microg x kg-1 x min-1) dobutamine for the detection of myocardial viability and high-dose dobutamine for the detection of myocardial ischemia (</=40 microg x kg-1 x min-1 with atropine </=1 mg) performed 12+/-6 days after an acute uncomplicated myocardial infarction and showing a moderate to severe resting left ventricular dysfunction (wall motion score index [WMSI] >1.6). Patients were followed up for 9+/-7 months. Low-dose dobutamine stress echocardiography identified myocardial viability in 130 patients (52%). Dobutamine-atropine stress echocardiography was positive for ischemia in 148 patients (47%) and negative in 166 patients (53%). During the follow-up, there were 12 cardiac deaths (3.8% of the total population). With the use of Cox proportional hazards model, delta low-dose WMSI (the variation between rest WMSI and low-dose WMSI) was shown to exert a protective effect by reducing cardiac death by 0.8 for each decrease in WMSI at low-dose dobutamine (coefficient, -0.2; hazard ratio, 0.8; P<0.03); WMSI at peak stress was the best predictor of cardiac death in this set of patients (hazard ratio, 14.9; P<0.0018).nnnCONCLUSIONSnIn medically treated patients with severe global left ventricular dysfunction early after acute uncomplicated myocardial infarction, the presence of myocardial viability identified as inotropic reserve after low-dose dobutamine is associated with a higher probability of survival. The higher the number of segments showing improvement of function, the better the impact is of myocardial viability on survival. The presence of inducible ischemia in this set of patients is the best predictor of cardiac death.

The atropine factor in pharmacologic stress echocardiography

Objectives. This study sought to compare, head to head, the two most popular pharmacologic stress echocardiographic tests-dipyridamole and dobutamin-with state of the art protocols in a large multicenter prospective study. Background. In the continuing quest for ideal diagnostic accuracy, pharmacologic stress echocardiography has quickly moved over the years from low to high dose regimens and is currently performed with atropine coadministration. Methods. Dobutamine (up to 40 μg/kg body weight per min) plus atropine (up to 1 mg over 4 h) and dipyridamole (up to 0.84 mg/kg per min over 10 h) plus atropine (up to 1 mg over 4 h) stress echocardiography was performed on different days, in random order and within 1 week in 360 patients with chest pain syndrome. Thirteen different echocardiographic laboratories, all fulfilling quality control criteria for stress echocardiographic reading, contributed to the study. Results. No major complications occurred during either test. The test was interrupted before achievement of predetermined end points for limiting side effects in 37 dobutamine-atropine and 7 dipyridamole-atropine stress echocardiographic studies (feasibility 90% vs. 98%, p < 0.01). Diagnostic accuracy was assessed in a subset of 110 patients with no obvious rest dyssynergy (akinesia or dyskinesia) who underwent coronary angiography independently of test results and within 1 week of testing. Significant coronary artery disease (≥50% diameter reduction in at least one major coronary vessel by quantitative coronary angiography) was found in 92 patients. Sensitivity for detection of coronary artery disease was 84% (77 of 92) for dobutamine-atropine and 82% (75 of 92) for dipyridamole-atropine stress echocardiography (p = NS), with a specificity of 89% (16 of 18) for dobutamine-atropine and 94% (17 of 18) for dipyridamole-atropine stress echocardiography (p = NS). A significant correlation was present between peak wall motion score index during dipyridamole-atropine and dobutamine-atropine stress echocardiography (r = 0.83, p < 0.0001). Conclusions. Dobutamine-atropine and dipyridamole-atropine stress echocardiography are safe and feasible, although submaximal studies are more frequent with dobutamine. The two stresses have comparable accuracy in the detection of angiographically assessed coronary artery disease, although dobutamine is marginally more sensitive and dipyridamole marginally more specific. Stratification of the ischemic response in the space domain is also comparable with the two stresses.

Prognostic value of dipyridamole echocardiography early after myocardial infarction in elderly patients

OBJECTIVESnThis study was conducted to assess the feasibility, safety and prognostic value of dipyridamole echocardiography in elderly patients recovering from an uncomplicated acute myocardial infarction in a subset analysis performed on the patients entered in the subproject residual ischemia of the Echo Persantine Italian Cooperative Study (EPIC).nnnBACKGROUNDnCoronary heart disease accounts for two thirds of all deaths in the age group > 65 years, and > 50% of all patients admitted to the hospital with acute myocardial infarction are > 65 years old. The prognostic value of dipyridamole-induced left ventricular dysfunction was clearly established in patients evaluated early after acute infarction.nnnMETHODSnIn a subgroup analysis of the Echo Persantine Italian Cooperative Study (EPIC), we assessed the value of dipyridamole echocardiography in predicting cardiac events in 190 elderly (> or = 65 years) patients (age 68.4 +/- 3.3 years, range 65 to 78; 147 men and 43 women) evaluated early (mean 10 days) after uncomplicated acute myocardial infarction and followed up for 14 +/- 9.8 months.nnnRESULTSnThere was no major side effect during dipyridamole echocardiography. A positive test result occurred in 85 patients (44.7%). During follow-up, there were 62 events (14 cardiac deaths, 7 nonfatal reinfarctions, 21 cases of class III or IV angina and 20 revascularization procedures). Of these 62 events, 44 occurred among 85 patients with positive dipyridamole echocardiography and 18 among 105 patients with negative dipyridamole echocardiography (52% vs. 17%, p < 0.001). Spontaneous events (death, reinfarction, angina) occurred in 31 patients with positive and in 11 with negative dipyridamole echocardiography (36% vs. 10%, p < 0.001). Hard events (myocardial infarction or death) occurred in 14 patients with positive and 7 with negative dipyridamole echocardiography (16% vs. 6%, p < 0.05). Death occurred in 11 patients with positive and in 3 with negative dipyridamole echocardiography (13% vs. 3%, p < 0.01). The positive predictive value of positive dipyridamole echocardiography and negative predictive value of negative dipyridamole echocardiography as related to the occurrence of all events in the follow-up period (death, reinfarction, angina, revascularization procedures) were 52% and 83%, respectively. The relative risk (that is, the relative risk of occurrence of future cardiac events in the group with positive dipyridamole echocardiography compared with that in those with negative dipyridamole echocardiography) was 3 for all events and 4.4 for death.nnnCONCLUSIONSnDipyridamole echocardiography was well tolerated by elderly patients and proved to be very effective in prognostic stratification early after uncomplicated acute myocardial infarction, even when only survival was considered.

Stress echocardiographic results predict risk of reinfarction early after uncomplicated acute myocardial infarction: Large-scale multicenter study

OBJECTIVESnThis study sought to assess the value of dipyridamole echocardiography in predicting reinfarction in patients evaluated early after uncomplicated acute myocardial infarction.nnnBACKGROUNDnThe identification of future nonfatal reinfarction seems an elusive target for physiologic testing. However, a large sample population is needed to detect minor differences in phenomena with a low event rate.nnnMETHODSnWe assessed the value of dipyridamole echocardiography in predicting reinfarction in 1,080 patients (mean [+/- SD] age 56 +/- 9 years; 926 men, 154 women) evaluated early (10 +/- 5 days) after uncomplicated acute myocardial infarction and followed up for 14 +/- 10 months.nnnRESULTSnSubmaximal studies due to limiting side effects occurred in 14 patients (1.3%); these test results were included in the analysis. Results of dipyridamole echocardiography were positive in 475 patients (44%). During follow-up, there were 50 reinfarctions: 45 nonfatal, 5 fatal (followed by cardiac death < or = 4 days after reinfarction). Reinfarction (either nonfatal or fatal) occurred in 30 patients with positive and 20 with negative results (6.3% vs. 3.3%, p < 0.01). Nonfatal reinfarction occurred in 25 patients with positive and 20 with negative results (5% vs. 3.3%, p < 0.05). Reinfarction was fatal in 5 of 30 patients with positive and in none of 20 with negative results (16.6% vs. 0%, p = 0.07). The relative risk of reinfarction was 1.9.nnnCONCLUSIONSnDipyridamole echocardiographic positivity identifies patients evaluated early after uncomplicated acute myocardial infarction at higher risk of reinfarction, especially fatal reinfarction.

1023-110 Stress Echo and the Risk of Reinfarction: A Fatal Attraction?

The identification of future reinfarction seems an elusive target for physiologic testing, consistently with the accepted notion that it is plaque type, rather than plaque size, that matters in provoking coronary occlusion. However, large sample populations are needed to detect phenomena with a low event rate. In addition, one should employ noninvasive stress test results that are tightly related to the extent and severity of CAD — in a stronger way than exercise-ECG. Aim of this study was to assess the capability of dipyridamole echocardiography test (DET) to predict reinfarction in patients evaluated early after acute uncomplicated myocardial infarction. In an updated analysis of the EPIC Study, we assessed the value of DET in predicting reinfarction in 1080 pts (age =xa056xa0±xa09, 926 men and 154 women) evaluated early (10xa0±xa05 days) after uncomplicated acute myocardial infarction and followed up for 14xa0±xa010 months. A positive test occurred in 475 pts (44%). During follow-up, there were 50 reinfarctions: 45 non-fatal, and 5 fatallfollowed by cardiac death afterxa0≤xa04 days from the reinfarction). Reinfarction (either nonfatal or fatal) occurred in 30 pts with positive and in 20 with negative DET (6.3 vs 3.3%, pxa0lxa00.01). Nonfatal reinfarction occurred in 25 patients with positive and in 20 with negative DET (5 vs 3%, Pxa0=xa00.05). Reinfarction was fatal in 5 out of 25 reinfarcted patients with positive and in none out of 20 reinfarcted patients with negative DET (20 vs 0%, Pxa0=xa00.07). The relative risk (i.e., the relative risk of the occurrence of future cardiac events in the group with negative DET) of reinfarction was 1.9. In conclusion, DET positivity identifies patients evaluated early after uncomplicated myocardial infarction at higher risk of reinfarction and especially of fatal reinfarction.