Usefulness of transesophageal atrial pacing combined with two-dimensional echocardiography (echo-pacing) in predicting the presence and site of residual jeopardized myocardium after uncomplicated acute myocardial infarction

The usefulness of transesophageal atrial pacing combined with 2-dimensional echocardiography (echo-pacing) in predicting the presence and site of jeopardized myocardium, defined as areas of myocardium perfused by a vessel with a stenosis > or = 75% or by a collateral circulation if the supplying vessel was occluded, was evaluated in 31 patients with uncomplicated acute myocardial infarction who underwent coronary angiography. All 5 patients without jeopardized myocardium had a negative test, whereas 24 of 26 with jeopardized muscle had a positive test (sensitivity 92%; specificity 100%). To identify the site of jeopardized myocardium, tests that were positive for development of new asynergies were analyzed further, distinguishing those positive in the infarct or remote zone. Seven of 8 patients with new asynergies in the remote zone had areas of jeopardized myocardium outside the territory of distribution of the infarct-related vessel, whereas only 2 of 12 with new asynergies in the infarct zone had areas of jeopardized myocardium outside that territory (p < 0.01), correctly predicting the site of jeopardized myocardium in 17 of 20 cases. In conclusion, echo-pacing is useful for detecting the presence and site of jeopardized myocardium after an acute myocardial infarction.

Prognostic value of dipyridamole echocardiography early after uncomplicated myocardial infarction: a large-scale, multicenter trial. The EPIC Study Group

PURPOSE

To determine the prognostic capability of the dipyridamole echocardiography test (DET) early after an acute myocardial infarction.

PATIENTS AND METHODS

On 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.

RESULTS

During 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.

CONCLUSIONS

DET 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 dobutamine echocardiography in patients with high pretest likelihood of coronary artery disease

To examine the value of transient regional asynergy on dobutamine stress echocardiography as a noninvasive predictor of future cardiac events, 51 symptomatic patients (aged 54 +/- 9 years) with suspected coronary artery disease (CAD) were studied using an incremental regimen of 5, 10, 15 and 20 micrograms/kg/min. Pretest likelihood of CAD was (mean +/- standard error of the percentage) 79.7 +/- 5.6% before and 83.4 +/- 5.2% after exercise electrocardiography using probability analysis based on age, sex and symptoms. Two-dimensional images were analyzed with reference to an 11-segment model and gave good interrater agreement. During 24 +/- 4 months (range 19 to 32) of follow-up, 23 patients had events (1 myocardial infarction, 9 unstable angina, 10 coronary bypass surgery, 3 coronary angioplasty) and 28 were event free. Age, proportion with baseline asynergy and both pretest echocardiographic ejection fraction and its response to dobutamine were similar in these 2 groups (all p = not significant). Transient asynergy was seen in 17 of 23 patients (74%) with and 8 of 28 patients (29%) without events (p < 0.01); 5 of 6 patients (83%) with involvement of 3 segments had events. Myocardial infarction or unstable angina occurred in 8 of 25 (32%) with a positive and 2 of 26 (8%) with a negative stress echocardiogram (p < 0.05). Both exercise duration (389 +/- 195 vs 517 +/- 237 seconds, p < 0.05) and time to diagnostic ST-segment shift (291 +/- 192 vs 447 +/- 212 seconds, p = 0.05) were shorter in those with inducible asynergy.(ABSTRACT TRUNCATED AT 250 WORDS)

Total Arterial Myocardial Revascularization Using New Composite Graft Techniques for Internal Mammary and/or Radial Arteries Conduits

Abstract Background: Total arterial myocardial revascularization (TAMR) is feasible because of the excellent long‐term patency of the arterial conduits. We present five new surgical configurations for TAMR. Methods: Between December 1998 and July 1999,34 patients with triple vessel disease underwent TAMR. All patients were in CCS 111 or IV. Sketelonized internal mammary arteries (IMAs) were used. The surgical techniques for TAMR consisted of Y or T composite grafts constructed between the in situ RlMA and free LIMA graft or radial artery (RA) conduit in three different configurations. Other techniques uses included a T graft constructed between the RA conduit and free LIMA graft in two configurations. Twenty‐six (76%) patients underwent contrast‐enhanced TTE color Doppler before and a after adenosine provocative test, and seven (20%) patients had postoperative coronary angiography. Results: Overall, 144 anastomoses (average number per patient, 4.2) were completed. One (2.9%) patient undergoing an inverted T graft technique died on postoperative day 2. Another patient (2.9%) undergoing the right Y graft technique using IMAs and RA suffered pe‐rioperative AM1 due to RA conduit vasospasm. Contrast‐enhanced TTE color Doppler before and after the adenosine provocative test and at 1 week postoperation revealed a coronary flow reserve (CFR) of 2.1 ± 0.2 in the LIMA stem, and in the RlMA stem, a CFR of 2.3 ± 0.3 (P < 0.007). In one patient undergoing the right Y graft technique using IMAs, we found only anomalous flow dynamic parameters of RIMA, suggesting a partial graft closure. The angio‐graphic examination revealed a free LIMA graft closure. At 6 ± 2.4 months after operation 33 patients were alive and free of angina. The IMAs stem evaluation by TTE color Doppler at follow‐up revealed a 2.45 ± 0.1 mm LIMA diameter and 2.6 ± 0.2 mm RlMA diameter, which was more than early postoperative data of P < 0.001 and P < 0.007, respectively. Conclusion: These data indicate that TAMR in young patients perhaps offers a better postoperative outcome and perhaps should be part of the surgical armamentarium. These techniques apply the “nontouch” principle and should be taken into consideration in patients with a heavily calcified aorta. Contrast‐enhanced TTE color Doppler is a safe, accurate, and noninvasive test, which allows assessment of IMA patency and CFR evaluation. The flow reserve of the IMAs seems to be adequate for multiple coronary anastomoses.