Results of treatment methods in cardiac arrest following coronary artery bypass grafting.

BACKGROUND AND AIM OF THE STUDY: Emergency re-revascularization and invasive/noninvasive interventions in intensive care unit (ICU) are two main treatment methods in cardiac arrest following coronary artery bypass grafting (CABG). We evaluated the short- and long-term consequences of these two methods and discussed the indications for re-revascularization. METHODS: Between 1998 and 2004, a total of 148 CABG patients, who were complicated with cardiac arrest, were treated with emergency re-revascularization (n = 36, group R) and ICU procedures (n = 112, group ICU). Re-revascularizations are mostly blind operations depending on clinical/hemodynamic criteria. These are: no response to resuscitation, recurrent tachycardia/fibrillation, and severe hemodynamic instability after resuscitation. Re-angiography could only be performed in 3.3% of the patients. Event-free survival of the groups was calculated by the Kaplan-Meier method. Events are: death, recurrent angina, myocardial infarction, functional capacity, and reintervention. RESULTS: Seventy percent of patients, who were complicated with cardiac arrest, had perioperative myocardial infarction (PMI). This rate was significantly higher in group R (p = 0.013). The major finding in group R was graft occlusion (91.6%). During in-hospital period, no difference was observed in mortality rates between the two groups. However, hemodynamic stabilization time (p = 0.012), duration of hospitalization (p = 0.00006), and mechanical support use (p = 0.003) significantly decreased by re-revascularization. During the mean 37.1 +/- 25.1 months of follow-up period, long-term mortality (p = 0.03) and event-free survival (p = 0.029) rates were significantly in favor of group R. CONCLUSION: Better short- and long-term results were observed in the re-revascularization group.

Irbesartan has a masking effect on dipyridamole stress induced myocardial perfusion defects.

BACKGROUND AND AIM: The angiotensin II type 1 (AT1) receptor antagonist irbesartan is used for the treatment of hypertension, but its anti-ischaemic effect is not yet known. Our aim was to assess the effect of irbesartan administration on the diagnostic yield of 99mTc sestamibi single photon emission computed tomography (SPECT) in patients with coronary artery disease (CAD) after dipyridamole stress. METHODS: Our study group consisted of 13 patients (11 men and two women; mean age, 53.3 +/- 10.6 years; body mass index, 26.9 +/- 3.3 kg x m(-2)) with angiographically documented CAD. All patients underwent SmTc sestamibi SPECT studies at rest, before (STRESS-1) and 2 weeks after irbesartan (150 mg daily) administration (STRESS-2) at dipyridamole stress. The extent and severity of defects were analysed by using visual and quantitative 99mTc sestamibi SPECT. RESULTS: The mean summed stress score was significantly higher during the STRESS-1 study than the STRESS-2 study (13.2 +/- 7.4 vs. 11 +/- 7.4, P=0.003). The mean size of perfusion defects at stress was significantly larger for the STRESS-1 group than the STRESS-2 group (17.8% +/- 2.85% vs. 15.3% +/- 2.95%, P=0.01). CONCLUSION: Our study showed that the AT1 receptor blocker irbesartan reduces the extent and severity of 99mTc sestamibi perfusion defects after dipyridamole stress in patients with CAD. Irbesartan may alter coronary blood flow reserve. The continued use of irbesartan before stress myocardial perfusion SPECT has a masking effect on stress induced myocardial perfusion defects. For this reason AT1 receptor blockers must be stopped before stress myocardial perfusion scintigraphic examinations.