[Coronary stents]. / Koronare Stents.

Since the introduction of coronary stents into clinical practice in the late 1980s, the number of stent implantations has increased so rapidly that stents are currently used in over 80 percent of all percutaneous coronary interventions. Although stent implantation was initially limited to large vessels with proximal and discrete lesions, improvements in stent design and implantation technique now allow their deployment in more complex lesions in smaller and diffusely diseased vessels. The overall acceptance of stents by interventional cardiologists can be attributed to favorable acute and longterm results compared to balloon angioplasty alone. Interventionalists have also been quick to embrace the smoother and larger lumen after stenting, in a shorter procedure time and with no additional risk, especially since the risk of stent thrombosis has been overcome by the introduction of dual antiplatelet therapy with Aspirin and Ticlopidine or Clopidogrel. Although restenosis and the need for reinterventions is lower after stenting compared to balloon angioplasty it still remains significant with about 15 percent of all patients returning for an other revascularization procedure. Meanwhile, a completely new generation of stents promises to eliminate the problem of restenosis. Drug-eluting stents, coated with antiproliferative substances have been successfully tested in small randomized trials. The restenosis rates at 6 and 12 months were extremely low ranging between zero and nine percent, with no clinical drawbacks so far. If these results hold up in longer follow up and in real life practice with more complex lesions stented the treatment of symptomatic coronary artery disease will change even more dramatically.

[Medicamentous management of acute coronary syndrome without ST segment elevation]. / Medikamentöses Management des akuten Koronarsyndroms ohne ST-Hebung.

Recent advances in the recognition and the treatment of acute coronary syndromes (ACS) have lead to an improvement in patient survival and definition of newer guidelines. Current strategies for the treatment of patients with non-ST-elevation ACS include anti-ischemic and antiplatelet medications. While aspirin, beta-blockers, heparin and nitrates are still common practice, the advent of newer anticoagulants (low molecular weight heparins) and antiplatelet agents (glycoprotein llb/IIIa inhibitors and thienopyridines like ticlopidin and clopidogrel) and, possibly, aggressive lipid lowering with statins have added significant benefits to the treatment options with a better prognosis for these patients. Moreover, aggressive medical strategies seem to be justified not only in high-risk patients but also in those that undergo an early invasive approach.

Post-prandial lipaemia and endothelial function among healthy men.

BACKGROUND: There is evidence that elevated post-prandial lipoproteins adversely affect progression and outcome of cardiovascular disease. Traditional risk factors are associated with impaired endothelium-mediated vasodilatation. However, studies regarding the relationship between post-prandial lipaemia and endothelial function are divergent. METHODS: Twelve healthy non-smokers were included in this study. Before and after intake of a lipid cocktail rich in dairy fat, we tested endothelial-dependent (acetylcholine 0.8-160 mg/min per 100 ml forearm tissue) and -independent (sodium nitroprussid 0.6 microgram/min) vascular function in the forearm vascular bed with plethysmography. Moreover, we tested the effect of 1-NMMA, a competitive inhibitor of the NO synthetase, on base-line flow. Extent of post-prandial lipaemia was assessed with the increases in triglycerides and retinyl-palmitate, a marker for intestinally derived lipoproteins. RESULTS: Baseline flow was higher after the test meal than during fasting (preprandial 6.5 +/- 0.5 ml/min* 100 ml tissue, post-prandial 8.0 +/- 0.5, p = 0.03), but similar after 1-NMMA (p = 0.85). Before and after intake of the test meal, there was no significant difference in acetylcholine-induced endothelium-dependent vasodilatation (repeated measurement ANOVA, p = 0.22). At the highest acetylcholine dose, forearm flow was very similar (fasting 18.4 +/- 1.9, post-prandial 17.9 +/- 1.9, p = 0.75). At maximum acetylcholine dose, there was a weak inverse but non-significant correlation between forearm flow and post-prandial triglyceridaemia (r = -0.38, p = 0.23) and intestinally derived lipoproteins (chylomicrons r = -0.29, p = 0.35, chylomicron remnants r = -0.15, p = 0.63). However, at the lowest acetylcholine dose there was a suggestion for a positive correlation between change in flow and post-prandial lipaemia (triglyceridaemia, r = 0.53, p = 0.07; chylomicrons, r = 0.41, p = 0.18 and remnants, r = 0.51, p = 0.09). Endothelium-independent vasodilatation in response to sodium nitroprusside did not significantly change (p = 0.23). CONCLUSION: Our results suggest that among healthy men post-prandial lipaemia is not associated with a notable impairment of endothelium-mediated vascular function in forearm resistance vessels.

Isradipine improves endothelium-dependent vasodilation in normotensive coronary artery disease patients with hypercholesterolemia.

OBJECTIVE: The dihydropyridine calcium antagonist isradipine has anti-atherosclerotic effects in animals and improves endothelium-mediated nitric oxide (NO)-dependent vasodilation in vitro. As improved endothelial function may be beneficial we investigated its effects in patients with a high likelihood of endothelial dysfunction. DESIGN: Thirty patients (two female, age 55.4 +/- 10.5 years) with known coronary artery disease and elevated (> 6 mmol/l) total cholesterol (cholesterol: mean 6.7 +/- 0.78 mmol/l) or a cholesterol/high density lipoproteins (HDL) ratio of > 5 not on lipid lowering therapy, participated in the study. Endothelial vasodilator function was assessed before and after double-blind, randomized administration of isradipine 5 mg/day or placebo for 3 months. METHODS: Endothelial function was assessed as forearm blood flow (FBF, venous occlusion plethysmography) responses to graded brachial artery infusions of acetylcholine (Ach), to the NO-synthase blocker NG-monomethyl-L-arginine (L-NMMA) and to the endothelium-independent vasodilator sodium nitroprusside (SNP). Blood pressure was measured either directly from the brachial arterial or by sphygmomanometer during clinic visits. RESULTS: Blood pressure was unchanged in both groups after 3 months (isradipine: 88.8 versus 92.1 mmHg; placebo: 81.0 versus 82.5 mmHg; NS) but cholesterol levels decreased similarly in both groups (isradipine: 6.7 versus 6.1 mmol/l, NS; placebo: 6.6 versus 5.9 mmol/l, P< 0.05). The vasodilator response to SNP and the decrease in FBF in response to blockade of NO synthesis by L-NMMA were unchanged in both groups. However, isradipine, but not placebo, enhanced the NO-dependent vasodilator response to Ach (P < 0.05). CONCLUSION: Isradipine improves acetylcholine-mediated vasodilation in hypercholesterolemic patients independent of changes in lipids or blood pressure.

Early sheath removal after coronary artery interventions with use of a suture-mediated closure device: clinical outcome and results of Doppler US evaluation.

PURPOSE: To evaluate the safety and efficacy of a suture-mediated closure device by comparing clinical outcomes of its use to those of manual compression and by using Doppler ultrasound (US) examination. MATERIALS AND METHODS: One hundred patients were randomized to treatment with either suture-mediated closure (n = 50) or manual compression (n = 50) after percutaneous transluminal coronary angioplasty (PTCA). The 50 patients randomized to receive suture-based treatment were allowed to get out of bed 4 hours after the procedure, whereas bed rest was required for 1 day in the patients treated with manual compression. All patients underwent clinical and US examination before getting out of bed and before discharge from the hospital. RESULTS: Forty-seven of 50 patients randomized to undergo suture-mediated closure were ambulatory the day of intervention, in 6.2 hours +/- 4.7 (mean +/- SE) after undergoing PTCA. The results of the US examination for these patients demonstrated the absence of bleeding complications after getting out of bed. All patients treated with use of manual compression were ambulatory the following day, 18.3 hours +/- 2.2 after undergoing PTCA. There was no difference in the occurrence of vascular complications between the two groups. CONCLUSION: Suture-based closure is a safe and effective method of achieving immediate hemostasis and shorter bed rest without increasing the risk of bleeding complications in PTCA procedures.

Use of an emboli containment and retrieval system during percutaneous coronary angioplasty in native coronary arteries.

BACKGROUND: Prevention of distal embolisation during percutaneous coronary revascularisation may be necessary to reduce postinterventional morbidity and mortality. METHODS AND RESULTS: We employed a newly developed emboli containment and retrieval system in native coronary arteries during percutaneous coronary angioplasty and stenting in 39 selected patients (mean age 58.9 +/- 10.1 years, 11 females) presenting with acute (n = 22; 8 LAD, 3 LCX, 11 RCA), subacute (n = 7; 2 LAD, 2 LCX, 3 RCA) or chronic (n = 6; 2 LAD, 4 RCA) total or subtotal occlusion of an infarct-related vessel, or with severe stenosis and symptoms of unstable angina (n = 4; 2 LAD, 2 RCA). Protection device-assisted angioplasty with stent implantation was uneventful in all patients with good angiographic results and normal postprocedural flow. Intermittent aggravation of anginal pain during inflation of the occlusive balloon (from 2.5 to a maximum of 25 minutes cumulative inflation time) was observed in 19 of the 36 conscious patients (7 with acute, 7 with subacute and 3 with chronic occlusion, and 2 with unstable angina), but caused neither interruption of distal occlusion nor haemodynamic instability. In 31 patients the aspirates contained visible debris. Histological analysis showed particles up to 12 mm in size, consisting of necrotic core, inflammatory cells, cholesterol debris, and old and fresh thrombi. In 8 patients the aspirated particles were too small to allow microscopic diagnosis or debris was absent. CONCLUSIONS: This preliminary report demonstrates the feasibility of using a protection device in native coronary arteries to prevent distal embolisation of particulate matter that is mobilised during percutaneous interventions. To the extent that this material contributes to the mechanisms of distal embolisation, noreflow and infarction, this device may help to reduce such complications. Appropriately designed trials are required to assess the clinical benefit of this system.

[Cost-effectiveness of primary PTCA and thrombolysis in the treatment of acute myocardial infarction]. / Kosteneffektivität von primärer PTCA und Thrombolyse bei der Behandlung des akuten Myokardinfarkts.

Clinical studies have shown a favourable outcome for primary PTCA compared with thrombolysis in the treatment of acute myocardial infarction. No data are available in Switzerland on the logistic and economic implications of treating more acute myocardial infarction patients by PTCA. The present paper sets out to assess all published studies comparing the cost-effectiveness of the two treatment modalities. A Medline search identified seven original cost and cost-effectiveness studies conducted between 1989 and 1999. According to these studies emergency PTCA generates costs similar to thrombolysis in the treatment of acute myocardial infarction if the infrastructure is available and there is high volume output. Better clinical results, as suggested by the literature, would result in a favourable cost-effectiveness ratio for primary PTCA.

[Stress echocardiography: analysis of results in 100 coronary angiography patients]. / Stress-Echokardiographie: Analyse der Resultate bei 100 koronarangiographierten Patienten.

Stress echocardiography is increasingly accepted as a reliable, noninvasive method for assessment of coronary artery disease. We retrospectively analysed the results of the first 100 consecutive patients (79 males, 62 +/- 10 years), who had both stress echocardiography and coronary angiography within 3 months without intercurrent revascularisation. In 71% of the patients treadmill- was performed and in 29% dobutamine-stress echocardiography. No patient had severe side effects. In the 100 patients, positive predictive accuracy for detection of significant coronary artery disease was 95% and for multivessel disease 80%. There was no significant difference in positive predictive value for detection of significant stenosis in the posterior perfusion territory (left circumflex, right coronary artery), with 79% compared to the anterior perfusion territory (86%, p = ns). Sensitivity for the left circumflex (60%) tended to be lower compared to the right coronary artery (76%) or left anterior descending coronary artery (82%) (p = ns). Despite poorer echocardiographic image quality in dobutamine-stress echocardiography patients, there was no significant difference between treadmill- and dobutamine-stress echocardiography regarding the positive predictive value for detection of coronary artery disease (98 vs 92%) or for recognition of multivessel disease (79 vs 79%) (p = ns). False results of stress echocardiography were rare (7%): false positive results were more common in the presence of wall motion abnormalities at rest, false negative results after an insufficient stress-induced increase in heart rate. Gender or left ventricular hypertrophy had no impact on stress echocardiography results (p = ns). In conclusion, both dobutamine- and treadmill-stress echocardiography are reliable, sensitive methods for non-invasive assessment of coronary artery disease; this is also valid in women and in left ventricular hypertrophy.

Echocardiography in the evaluation of systolic murmurs of unknown cause.

PURPOSE: Systolic murmurs are common, and it is important to know whether physical examination can reliably determine their cause. Therefore, we prospectively assessed the diagnostic accuracy of a cardiac examination in patients without previous echocardiography who were referred for evaluation of a systolic murmur. SUBJECTS AND METHODS: In 100 consecutive adults (mean [+/- SD] age of 58 +/- 22 years) who were referred for a systolic murmur of unknown cause, the diagnostic accuracy of the cardiac examination by cardiologists (without provision of clinical history, electrocardiogram, or chest radiograph) was compared with the results of echocardiography. RESULTS: The echocardiographic findings included a normal examination (functional murmur) in 21 patients, aortic stenosis in 29 patients, mitral regurgitation in 30 patients, left or right intraventricular pressure gradient in 11 patients, mitral valve prolapse in 11 patients, ventricular septal defect in 4 patients, hypertrophic obstructive cardiomyopathy in 3 patients, and associated aortic regurgitation in 28 patients. In 28 (35%) of the 79 patients with organic heart disease, more than one abnormality was found; combined aortic and mitral valve disease was the most frequent combination (n = 22). The sensitivity of the cardiac examination was acceptable for detecting ventricular septal defect (100% [4 of 4]), isolated mitral regurgitation (88% [26 of 36]), aortic stenosis (71% [21 of 29]), and a functional murmur (67% [14 of 21]), but not for intraventricular pressure gradients (18% [2 of 11]), aortic regurgitation (21% [6 of 28]), combined aortic and mitral valve disease (55% [6 of 11]), and mitral valve prolapse (55% [12 of 22]). In 6 patients, the degree of aortic stenosis was misjudged on the clinical examination, mainly because of a severely diminished left ventricular ejection fraction. Significant heart disease was missed completely in only 2 patients. CONCLUSION: In adults with a systolic murmur of unknown cause, a functional murmur can usually be distinguished from an organic murmur. However, the ability of the cardiac examination to assess the exact cause of the murmur is limited, especially if more than one lesion is present. Thus, echocardiography should be performed in patients with systolic murmurs of unknown cause who are suspected of having significant heart disease.

[Check-up examinations from the cardiologic viewpoint]. / Checkup-Untersuchungen aus kardiologischer Sicht.

The concept of the primary prevention of coronary disease is certainly widely accepted today and supports check-up visits of apparently healthy persons. The goals of check-up's viewed by the cardiologist are the detection of coronary risk factors and the identification of asymptomatic patients with coronary disease to initial preventive measures. In some instances, a personal health problem forces the patient to a check-up visit. The major coronary risk factors of heredity, cigarette-smoking, hypercholesteremia, hypertension can be detected by taking the history, performing a physical examination and a blood-sampling for cholesterol. Additional investigations such as an ECG or an exercise-test are only indicated in symptomatic patients or in persons at high coronary risk.

To stent or not to stent.

Coronary artery stenting has definitely been proven to improve results of percutaneous revascularisation in a large number of patients. Stenting reduces restenosis in large vessels above 3 mm diameter. Stenting has not solved the problem of restenosis but in spite of the inevitable in-stent restenosis due to neointimal proliferation seems to yield better long-term results than conventional PTCA. Adjunctive pharmacological treatment with aspirin and clopidogrel in combination with improved stent deployment techniques has reduced the incidence of subacute stent thrombosis. GP IIb/IIIa inhibition is a promising mean for the reduction of procedure related ischaemic events and complications not only with stent implantation but also with conventional PTCA. Other new devices may further influence the treatment choices of stenting versus conventional PTCA in the future. Novel approaches such as brachytherapy and molecular genetic approaches to reduce in-stent restenosis are currently being investigated but to date no conclusions can be drawn as to their future place in clinical practice. From a mechanistic standpoint it seems obvious to give all our efforts to protect patients with coronary atherosclerosis from loss of myocardium either with coronary artery bypass grafting or percutaneous revascularisation. As both approaches are palliative in nature, it may be useful to attempt percutaneous revascularisation in patients amenable to this therapy and thus obviate or delay the need for definitive revascularisation by coronary artery bypass grafting. At the end of this discussion we would like to remind that medical therapy for coronary artery disease is of utmost importance as all revascularisation procedures do not influence the underlying disease. Besides symptomatic relief of angina, treatment of heart failure, and other beneficial strategies to improve endothelial function, medical therapy with lipid lowering compounds together with risk factor control offers the possibility to delay progression of coronary artery disease.

Acute hemodynamic effects of alternate and combined site pacing in patients after cardiac surgery.

We hypothesized that pacing at sites other than the right ventricular (RV) apex or at two or more ventricular sites would activate the myocardium more rapidly and improve cardiac function in patients undergoing coronary revascularization or aortic valve replacement. Epicardial electrodes were placed on the right atrium (A), RV paraseptal area close to the RV apex (B), RV outflow tract (C), LV apex (D), in patients undergoing bypass surgery. At constant rate and AV delay, we measured CO during A pacing, DVI pacing at B, C, D, and various combinations of sites in random order in ten patients with EF > 50% and 27 patients with EF < or = 50%. When pacing at two sites, we made one electrode a cathode and one an anode and noted two distinct thresholds by careful observation of the 12-lead ECG. There were no significant differences in CO, systemic vascular resistance, systolic, or mean arterial pressure. Significant differences were noted in QRS duration, which increased progressively going from AAI to 3-site, 2-site, and single site pacing (P < 0.05 each comparison). Thus: (1) QRS duration correlated inversely with the number of ventricular sites paced; (2) despite this, CO did not improve irrespective of baseline EF; (3) multisite pacing produced multiple distinct thresholds which appeared to be related to the number of sites paced, and (4) unique ECG patterns confirmed multisite pacing.

[Type 2 diabetes mellitus and coronary heart disease]. / Diabetes mellitus Typ 2 und koronare Herzkrankheit.

Coronary artery disease is the most common cause of morbidity and mortality in subjects with type 2 diabetes mellitus. The risk of coronary artery disease, myocardial infarction and mortality from myocardial infarction is markedly increased in type 2 diabetic patients compared with non-diabetics. Diabetic patients with acute myocardial infarction should receive thrombolytic therapy as rapidly as possible and for the same indications as non-diabetics. Diabetic retinopathy is not a contraindication to treatment. The management of diabetic patients should also include medication with aspirin, beta-blockers and ACE-inhibitors. An insulin-glucose infusion during acute myocardial infarction, followed by insulin injections subcutaneously, reduces mortality by about 30% after 12 months and improves long-term prognosis. Thus, insulin-glucose infusion in diabetic patients with acute myocardial infarction, especially in those with a high blood glucose level (> 11 mmol/l), seems advisable. Diabetic patients benefit from secondary prevention by drug therapy (aspirin, lipid lowering with statins, beta-blockers and ACE-inhibitors) to the same extent as, or more than, non-diabetic patients.

Sulfonylureas and ischaemic preconditioning; a double-blind, placebo-controlled evaluation of glimepiride and glibenclamide.

AIMS: Glimepiride is a new sulfonylurea for diabetes treatment which is supposed to impact less on extra-pancreatic ATP-dependent K+ channels than the conventional drug glibenclamide. This study was performed to evaluate whether this results in a better maintenance of ATP-dependent K+ channel mediated ischaemic myocardial preconditioning. METHODS AND RESULTS: In a double-blind placebo-controlled study the period of total coronary occlusion during balloon angioplasty of high grade coronary artery stenoses was used as a model to compare the effects of both drugs. Quantification of myocardial ischaemia was achieved by recording the intracoronary ECG and the time to the occurrence of angina during vessel occlusion. All patients underwent three dilatations. The first dilatation (dilatation 1) served to determine the severity of ischaemia during vessel occlusion. During dilatation 2, baseline values were recorded. Thereafter, glimepiride (15 patients: 1.162 mg), glibenclamide (15 patients: 2.54 mg) or placebo (15 patients) were intravenously administered over 12 min. Dilatation 3 started 10 min after the beginning of the drug administration. Mean ST segment shifts in the placebo group decreased by 35% (dilatation 2: 0.23; dilatation 3:0.15 mV; CI -0.55 to 0.00 mV; P=0.049). A similar reduction also occurred in the glimepiride group, in which repetitive balloon occlusion led to a 34% reduction (dilatation 2: 0.35; dilatation 3: 0.23 mV; CI -0.21 to -0.02 mV; P=0.01). There was little influence however, on mean ST segment shifts in the glibenclamide group (dilatation 2 and dilatation 3: 0.24 mV; CI -0.10 to 0.25 mV; P=0.34). Accordingly, time to angina during balloon occlusion slightly increased (by 30%) in the placebo group (dilatation 2: 37 s; dilatation 3: 48 s; CI 0.0 to 15.0 s; P=0.16); increased by 13% in the glimepiride group (dilatation 2: 40 s; dilatation 3: 45 s; CI 0.0 to 14.0 s; P=0023); and remained unchanged in the glibenclamide group (dilatation 2 and dilatation 3: 30 s; CI -7.5 to 7.5 s; P=0.67). CONCLUSION: These results show that glimepiride maintains myocardial preconditioning, while glibenclamide might be able to prevent it.

[Lipid-lowering therapy in patients with coronary disease: proportion of patients requiring treatment according to recommendations of the Swiss Society of Cardiology]. / Lipidsenkende Therapie bei Patienten mit koronarer Herzkrankheit: Behandlungsbedürftigkeit gemäss den schweizerischen Empfehlungen 1999.

BACKGROUND: Recent studies have confirmed that treatment with lipid-lowering drugs decreases cardiovascular morbidity and mortality in primary as well as secondary prevention of cardiovascular diseases. In 1999, new Swiss recommendations for treatment with lipid-lowering drugs have been published. We therefore performed a study to estimate the proportion of patients with coronary artery disease requiring lipid-lowering drugs. METHODS: We included 637 patients with coronary heart disease who were referred for coronary angiography during 1991-1993. We calculated the proportion of patients requiring lipid-lowering drugs according to the new Swiss guidelines, and compared them with European and US guidelines. RESULTS: According to the 1999 Swiss recommendations, 79% of the study population would have qualified for lipid-lowering treatment (males 80%, females 78%; patients aged up to 69 years 80%, patients aged 70 years and over 73%). Agreement with both the Recommendations of the Second Joint Task Force of European and other Societies on Coronary Prevention, and the ACC/AHA Guidelines for Management of Patients with Acute Myocardial Infarction, was 96% (Kappa 0.79 and 0.83 respectively). CONCLUSION: A large proportion of patients with coronary artery disease qualifies for treatment with lipid-lowering drugs. The new Swiss recommendations closely agree with European and US guidelines.