Treating thrombus in the coronary arteries.

Primary percutaneous coronary intervention (PCI) has greatly improved outcomes in patients with ST-elevation myocardial infarction (STEMI) and has, therefore, become the preferred reperfusion strategy for this patient group. The goal of primary PCI is to achieve a thrombolysis in myocardial infarction (TIMI) 3 flow and also to restore adequate perfusion at the myocardial level. Distal thrombus embolization during primary PCI occurs frequently and is also associated with compromised long-term outcomes. In this article, we provide an overview of the treatment of thrombus and the role of thrombectomy in PCI for STEMI.

Coronary vessel diameters during and after primary percutaneous coronary artery intervention.

BACKGROUND: Primary percutaneous coronary intervention (P-PCI) is the gold standard treatment for acute coronary syndromes. Plasma levels of catecholamines and other vasopressors are elevated during acute myocardial infarction (AMI) and coronary vasoconstriction is frequent. We aimed to compare the reference vessel diameter (RVD) of the infarct-related artery (IRA) during primary PCI and after an average of 3 days. METHODS: Coronary angiography (CAG) was performed on 58 patients with acute ST-segment elevation myocardial infarction (STEMI) and TIMI 3 flow after P-PCI (43 men, 15 women; mean age, 55.5 ± 10 years). TIMI 3 flow was achieved either by simple balloon dilatation and/or thrombus aspiration. Lesion length, RVD, minimal lumen diameter (MLD), mean vessel diameter (meanD), and area of stenosis were compared during P-PCI and follow-up CAG. RESULTS: RVD, MLD, and meanD values were significantly higher during the follow-up CAG than after P-PCI (RVD 2.7 ± 0.7 mm vs. 2.9 ± 0.7 mm, p = 0.001; MLD 1.5 ± 0.5 mm vs. 1.7 ± 0.4 mm, p = 0.002; meanD 2.2 ± 0.5 mm vs. 2.4 ± 0.5 mm, p = 0.001). Area of stenosis values were significantly lower during the follow-up CAG than after primary PCI (69.5 ± 16.5 % vs. 62.1 ± 15 %, p = 0.001). Lesion lengths were not statistically significant during the follow-up CAG and primary PCI (lesion length 24.0 ± 10.8 mm vs. 22.1 ± 8.8 mm, p > 0.05). CONCLUSION: This study showed that RVD was higher at the follow-up CAG a few days after AMI in patients who had TIMI 3 flow after P-PCI with simple balloon dilatation and/or thrombus aspiration. A delay of a few days for stent implantation in P-PCI allows for larger-diameter stent use and may help to reduce stent thrombosis and restenosis rates.

The effect of nebivolol on internal mammary artery blood flow during coronary artery bypass graft surgery.

BACKGROUND: During coronary artery bypass grafting (CABG), one of the most important complications related to the internal mammary artery (IMA) is perioperative spasm. Nebivolol causes endothelium-dependent vascular relaxation by increasing nitric oxide (NO) release and prevents endothelial dysfunction in long-term use. In our study, we measured the effect of a third generation beta blocker, nebivolol, on the flow dynamics of IMA grafts. METHODS: We recruited 90 hypertensive patients undergoing isolated CABG operation, who were divided into three groups and each group included 30 patients: Group 1 patients were under antihypertensive treatment other than beta-blockers (angiontensin-converting enzyme [ACE] inhibitors, calcium channel blockers or diuretics; monotherapy or combination therapy), Group 2 received metoprolol (50 mg/day) and Group 3 received nebivolol (5 mg/day). These antihypertensive therapies were given for at least one week before the operation and continued thereafter. IMA blood flow volume was measured for one minute just before cardiopulmonary bypass (measurement A) and before left internal mammary artery (LIMA)-left anterior descending (LAD) artery anastomosis (measurement B) in the three groups. Cardiac output measurements were also achieved simultaneously. RESULTS: The measurement A results were 56.3 ± 36.2, 54.6 ± 28.1 and 66.8 ± 34.2 mL/min in Groups 1, 2 and 3, respectively (p<0.05). The measurement B results were 78.3 ± 29.6, 80 ± 28.8 and 91.1 ± 40.8 mL/min in Groups 1, 2 and 3 (p<0.05), respectively. There were no differences in cardiac outputs among the groups; 5.2 ± 1.4, 5.0 ± 1.6 and 5.3 ± 1.1 L/min (p>0.05). While the cardiac outputs were similar within the three groups, the IMA free flow volume was higher in the nebivolol group after local papaverine use. CONCLUSION: Nebivolol might represent a good choice in hypertensive patients undergoing cardiac surgery by preventing perioperative myocardial hypoperfusion which increases early morbidity and mortality.

Safety of balloon pre-dilatation in the treatment of severe carotid artery stenosis.

AIM: To assess early outcome of predilatation prior stenting of severe carotid artery stenosis and to evaluate early major adverse cardiovascular and cerebral events (MACCE). PATIENTS AND METHODS: The study group consisted of 265 consecutive patients (200 males, 65 female, mean age 66.7 ± 8.6 years) in whom 275 percutaneous transluminal angioplasty (PTA) procedures of carotid arteries were performed. Staged carotid stenting was performed in patients with bilateral carotid stenosis. Neuroprotection with a distal protection device was used in all cases. The patients were divided into two groups: direct carotid stent implantation without previous pre-dilation was performed in 233 patients (direct stenting group) and predilatation was performed in 42 patients (predilatation group). Early events were recorded and analyzed subsequently. RESULTS: We treated 275 carotid stenoses and the stent was implanted in all patients. Ten patients (3.7%) were treated by staged carotid artery stenting (CAS) due to bilateral carotid artery disease. The technical success rate was 97.1%. During 1-month follow-up, the prevalence of primary endpoint was 2.18%. The prevalence of MACCE at 30 days was higher in the predilatation group (2.4% vs. 2.1%; p = 0.924). Also periprocedural rate of hypotension was higher in predilatation group (7.1% vs. 1.7%; p = 0.04). CONCLUSIONS: Balloon predilatation prior to stenting can be performed to treat severe carotid artery stenosis with acceptable periprocedural complication rate.

Accordion effect in a thin-strut coronary stent.

Longitudinal compression (accordion effect) of modern thinner-strut stents has been recently recognised. We report a typical case of longitudinal stent compression caused by a post-dilatation balloon.