Benno Hennen

Beneficial Effects of Immediate Stenting After Thrombolysis in Acute Myocardial Infarction

OBJECTIVES The Southwest German Interventional Study in Acute Myocardial Infarction (SIAM III) investigated potentially beneficial effects of immediate stenting after thrombolysis as opposed to a more conservative treatment regimen. BACKGROUND Treatment of acute myocardial infarction (AMI) by thrombolysis is compromised by Thrombolysis In Myocardial Infarction (TIMI) 3 flow rates of only 60% and high re-occlusion rates of the infarct-related artery (IRA). Older studies showed no benefit of coronary angioplasty after thrombolysis compared with thrombolytic therapy alone. This observation has been challenged by the superiority of primary stenting over balloon angioplasty in AMI. METHODS The SIAM III study was a multicenter, randomized, prospective, controlled trial in patients receiving thrombolysis in AMI (<12 h). Patients of group I were transferred within 6 h after thrombolysis for coronary angiography, including stenting of the IRA. Group II received elective coronary angiography two weeks after thrombolysis with stenting of the IRA. RESULTS A total of 197 patients were randomized, 163 patients fulfilled the secondary (angiographic) inclusion criteria (82 in group I, 81 in group II). Immediate stenting was associated with a significant reduction of the combined end point after six months (ischemic events, death, reinfarction, target lesion revascularization 25.6% vs. 50.6%, p = 0.001). CONCLUSIONS Immediate stenting after thrombolysis leads to a significant reduction of cardiac events compared with a more conservative approach including delayed stenting after two weeks.

Rapid Effect of 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Inhibition on Coronary Endothelial Function

Abstract— Treatment with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) decreases cardiovascular event rates in hypercholesterolemic patients. Whether statins exert effects within 24 hours on the coronary vasculature in patients with endothelial dysfunction has not been elucidated. Twenty-seven patients with stable angina pectoris and average low-density lipoprotein cholesterol concentrations of 138±9 mg/dL at baseline were allocated to treatment with placebo (14 patients) or 40 mg/d pravastatin (13 patients) in a randomized, double-blind, prospective trial. Coronary endothelial function was assessed before and 24 hours after single treatment by quantitative coronary angiography during intracoronary infusion of nitroglycerin or increasing concentrations of acetylcholine (0.01, 0.1, and 1 &mgr;mol/L). Coronary blood flow reserve was measured by Doppler velocimetry during adenosine infusion. Intracoronary acetylcholine infusion induced abnormal vasoconstriction in both groups before treatment, indicating coronary endothelial dysfunction. Treatment with a single oral 40-mg dose of pravastatin significantly attenuated acetylcholine-mediated vasoconstriction after 24 hours (mean±SE decrease in luminal diameter before and after treatment: 0.01 &mgr;mol/L, 6.1±2.2% versus 3.0±1.2%; 0.1 &mgr;mol/L, 15.6±2.6% versus 7.4±1.8%; P <0.05; 1 &mgr;mol/L, 22.9±2.9% versus 13.2±2.6%; P <0.05). There was no significant difference in the response to acetylcholine in the placebo group (8.1±2.4% versus 9.7±2.4%, 16.1±2.9% versus 16.8±3.2%, and 21.4±3.9% versus 23.3±4.2%). The response to nitroglycerin infusion was not altered in both groups. Increase in coronary blood flow in response to adenosine and coronary flow reserve remained unchanged during placebo and statin treatment. Serum concentrations of blood lipids and high-sensitive C-reactive protein were not significantly altered after 24 hours in response to placebo or pravastatin therapy. Statin treatment improves endothelium-dependent coronary vasomotion within 24 hours in the absence of significant cholesterol reduction. The full text of this article is available online at http://www.circresaha.org.

T grafts with the right internal thoracic artery to left internal thoracic artery versus the left internal thoracic artery and radial artery: Flow dynamics in the internal thoracic artery main stem

OBJECTIVE Complete arterial coronary artery bypass grafting with 2 grafts can be achieved even in triple vessel disease by use of a T configuration. There is still uncertainty whether the coronary flow reserve in the main stem of the left internal thoracic artery is sufficient to supply more than 1 anastomosed coronary vessel. METHODS Between March 1996 and February 1999, 251 patients with multivessel coronary artery disease underwent complete arterial revascularization with T grafts, using either the left internal thoracic artery with the free right internal thoracic artery graft (n = 73, group I) or the left internal thoracic artery and radial artery (n = 178, group II). A mean of 4.0 (group I) versus 4.3 (group II) coronary vessels were anastomosed per patient. One week (n = 92) and 6 months (n = 28) after the operation, flow was measured in the proximal left internal thoracic artery with a Doppler guide wire. Maximum flow was determined after injection of adenosine (30 microg). RESULTS The in-hospital mortality was 2.7% (group I) versus 2.3% (group II). At angiography (n = 142, 56.6%) the patency rate was 96.3% (group I) versus 98.2% (group II). There was no significant difference between baseline flow, maximum flow, and coronary flow reserve between the 2 groups. Coronary flow reserve increased in both groups within the first 6 postoperative months (group I, 1.85 +/- 0.31 vs 2.77 +/- 0.77, P =.0002; group II, 1.82 +/- 0.4 vs 2.53 +/- 0.73, P =.009). CONCLUSION Both variants of T grafts allow for complete arterial revascularization with good perioperative results. The flow reserve of the proximal internal thoracic artery is adequate for multiple coronary anastomoses irrespective of the choice of the second arterial graft.

Long-term follow-up of a randomized study of primary stenting versus angioplasty in acute myocardial infarction

PURPOSE Primary stenting leads to better short-term outcomes than does balloon angioplasty among patients with acute myocardial infarction, but there are no data available on long-term follow-up. SUBJECTS AND METHODS We designed a randomized study with long-term follow-up to compare primary angioplasty with angioplasty accompanied by implantation of a silicon carbide-coated stent in patients within 24 hours after the onset of acute myocardial infarction. All 88 patients had lesions that were suitable for coronary stenting. RESULTS There were 44 patients in each of the randomization groups. During long-term follow-up (mean +/- SD: 710+/-282 days), primary stenting was associated with a reduction in the combined endpoint of death, reinfarction, or target vessel revascularization (10 [23%] versus 19 [43%], P = 0.03); death (4 [9%] versus 8 [18%], P = 0.18); reinfarction (1 [2%] versus 4 [9%], P = 0.18); and target lesion revascularization (7 [16%] versus 15 [34%], P = 0.04). Rehospitalization due to ischemic events (unstable angina or reinfarction) was also less frequent in the stent group (6 [14%] versus 10 [23%], P = 0.20). CONCLUSION Primary stenting in acute myocardial infarction is significantly superior to angioplasty alone in both short-term and long-term follow-up.

Flow wire measurements after complete arterial coronary revascularization with T-grafts

BACKGROUND The T-graft procedure achieves complete arterial revascularization in coronary three-vessel disease. In this technique, all bypass anastomoses are supplied by the left internal mammary artery (IMA). This prospective study explores the question of whether the quantitative flow in such grafts is influenced by the pathology in the native coronary arteries. METHODS Eighty-two patients with coronary three-vessel disease were studied after complete arterial coronary revascularization with T-grafts. Quantitative flow and coronary flow reserve were measured in the proximal IMA with a Doppler guide wire. Three groups were compared: group 1, all native coronary arteries were stenosed but patent (n = 31); group 2, one occluded native coronary vessel (n = 33); group 3, two or more occluded native coronary arteries (n = 18). RESULTS Quantitative flow was significantly higher in group 3 than in group 2 at 1 week (93.9 +/- 39.5 vs 75.8 +/- 27.3 mL/min, p < 0.05) and 6 months postoperatively (86.0 +/- 40.1 vs. 69.1 +/- 35.5 mL/min, p < 0.05). Flow in group 2 was significantly (p < 0.05) higher than in group 1 (1 week: 58.0 +/- 28.4 mL/min, 6 months: 55.2 +/- 29.2 mL/min) in both examinations. There were no significant differences in coronary flow reserve between the three groups (1: 2.88 +/- 0.97, 2: 2.84 +/- 0.96, 3: 2.74 +/- 0.94). CONCLUSIONS After complete arterial revascularization with T-grafts, the quantitative flow in the IMA is influenced by the status of the native coronary arteries. As a result of competitive flow phenomena, blood flow in the bypasses is significantly lower when the coronary arteries are affected only by stenosis.

Effect of X-Ray Contrast Media on Blood Flow Properties after Coronary Angiography

In vitro studies suggest that ionic and nonionic X-ray contrast media have different effects on rheological parameters. The risk of thrombotic complications in coronary interventions was reported to be lower using ionic contrast media. The aim of the present study was to compare the effects of different types of contrast media on rheological parameters after coronary angiography. Sixty patients were randomized to four groups: ioxaglate 320 (dimeric, ionic, n = 18), iomeprol 400 (monomeric, nonionic, n = 12), iobitridol 350 (monomeric, nonionic, n = 12), and iodixanol 320 (dimeric, nonionic, n = 18). Blood samples were collected via the side port of the arterial sheath immediately before and at the end of coronary angiography. In our study, all types of contrast media caused a significant decrease in haematocrit (Hct), plasma viscosity (PV), erythrocyte aggregation (EA), and in the platelet reactivity index (PRI). The most pronounced decrease in Hct was found using the ionic dimer ioxaglate. There were no significant differences between the contrast media with respect to their effects on PV, EA, and PRI.

Cardiac Imaging in Isolated Noncompaction of Ventricular Myocardium

A 42-year-old man with previously diagnosed dilated cardiomyopathy due to alcohol abuse was referred to our clinic for further diagnostic procedures. Cardiac catheterization (cine loop 1: Figure 1 and Movie I) demonstrated left ventricular dilatation with obviously hypokinetic basal and apical segments, a restrictive filling pattern (“square root sign”), moderate mitralic regurgitation, and no obstruction of the left ventricular outflow tract. Impaired systolic function was confirmed by an ejection fraction of 28%. After injection of a contrast medium, …

Impaired flow in left internal mammary artery grafts due to subclavian artery stenosis

We report two cases of patients with left internal mammary artery (LIMA) grafts impaired by proximal stenosis of the subclavian artery. The functional impact of the subclavian lesions was investigated using flow-wire. The hemodynamic relevance of the lesions could be documented with the functional flow measurements in both instances. The relevance of preoperative evaluation of the subclavian artery is emphasized when it is planned to use the LIMA as coronary bypass. Moreover, the case reports indicate that percutaneous intervention of the subclavian artery is an effective treatment modality to restore adequate flow in the LIMA.

Plasma lidocaine concentrations after local anesthesia of the groin for cardiac catheterization.

This study aimed to investigate serum lidocaine concentrations after subcutaneous infiltration of the groin for cardiac catheterization. One hundred twenty‐six patients for planned heart catheterization received five different dosages (5–25 ml) of lidocaine 2% for local anesthesia of the groin in a randomized manner. All of them received an arterial sheath and 13 received both an arterial sheath and a venous sheath for right heart catheterization. Blood samples were taken before as well as 15, 30, and 120 min after subcutaneous application of the drug. Although in 33 patients with an arterial sheath (no venous sheath) excessive doses of lidocaine 2% (20–25 ml) were used, neither symptoms of intoxication nor toxic plasma levels were observed. However, in patients receiving an additional venous sheath, toxic plasma levels were obtained in a third of the cases. One of them showed symptoms of intoxication. Cathet Cardiovasc Intervent 2002;57:342–345.

Röntgenkontrastmittel in der invasiven Kardiologie, Nebenwirkungen und differenzierter Einsatz

Die für die invasive Kardiologie heute verfügbaren ionischen und nichtionischen Röntgenkontrastmittel (RKM) besitzen eine ausgezeichnete Verträglichkeit. Das Nebenwirkungsprofil wird neben substanzspezifischen Eigenschaften vor allem durch die Viskosität, die Osmolalität und den Ionengehalt bestimmt. Neben den in Deutschland bevorzugten nichtionischen RKM stellt das ionische Ioxaglat für Risikointerventionen, aufgrund der ausgeprägteren antikoagulatorischen Eigenschaften, eine wichtige Alternative dar. Problempatienten mit bekannter Kontrastmittelunverträglichkeit lassen sich durch vorherige Verabreichung von Antihistaminika und Kortikoiden ohne schwerwiegende Komplikationen untersuchen. Bei niereninsuffizienten Patienten mit eingeschränkter Nierenfunktion erweist sich die Hydratation als effektive prophylaktische Maßnahme. For invasive catheter procedures both ionic and nonionic contrast media (CM) with excellent tolerability are available. The governing practical factors for CM are X-ray opacity and biocompatibility. Tolerability of a contrast medium is governed among its physical properties by its viscosity, osmolality, and ionic concentration. In Germany the nonionic CM are currently preferred. Because of its low thrombotic complications, the ionic CM Ioxaglat is an important alternative in high risk interventions. In patients with known CM incompatibility, the prophylactic application of H1-receptor antagonists and corticosteroids allows catheterization safely without complications. In impaired renal function, hydration is the most effective prophylactic measure to be taken.