Relation between admission time, haemodynamic measurements, and prognosis in acute myocardial infarction

[Therapy of cardiogenic shock : A success story of German cardiology]

In contrast to the situation in the 1960s and 1970s, the mortality risk for patients with myocardial infarction has been clearly reduced, particularly for those with myocardial infarction with cardiogenic shock (MICS). Approximately 5‑10 % of patients with a myocardial infarction are affected by a MICS and the mortality risk is between 30 % and 50 %. The primary percutaneous coronary intervention with stent implantation should be carried out as quickly as possible in order to reduce the mortality to around 20 %. This article gives an overview of the currently available options for conservative and fibrinolytic treatment of MICS, of the interventional treatment of cardiogenic shock in the era of intravenous and intracoronary infarct treatment as well as without thrombolysis. In addition, the currently available mechanical support systems and the possibilities for surveillance and monitoring of patients are presented.

Diuretics in postinfarction heart failure

Severe left ventricular failure, as evidenced by radiographic pulmonary edema or raised left ventricular filling pressure, accompanying acute myocardial infarction, carries a high mortality risk. In this situation, the intravenous loop-diuretic furosemide induces a rapid reduction in the raised left ventricular filling pressure due to an immediate and substantial increase in systemic venous compliance accompanied by increasing diuresis. This diuretic-induced venodilatation is probably due to the release of prostaglandins. The transient systemic arterial constriction and small increase in systemic blood pressure that follows intravenous furosemide probably results from the release of renin and subsequent activation of angiotensin. These diuretic induced hemodynamic changes are accompanied by restoration of the vasodilator reflex, which enables the heart to accommodate an acute volume load. Orally administered loop diuretics achieve slower, but similar, directional hemodynamic changes. There is no information on hemodynamic or neuroendocrine dose-response effects of loop diuretics, and there is no information pertaining to the use of other diuretic groups in this situation. The hemodynamic changes induced by furosemide summate with the changes induced by other anti-heart-failure drugs. In this subset of patients with acute myocardial infarction and severe heart failure, the influence of the diuretics on morbidity incidence and mortality risk remains to be measured.

Coronary prognostic index for the Chinese

A coronary prognostic index (CPI) for the prediction of mortality of patients with acute myocardial infarction (AMI) has been constructed with data from 644 Chinese patients in Hong Kong. According to this CPI, patients with AMI could be divided into subgroups with increasing hospital mortality from 1.6% to 100%, depending on their ages, blood pressure, heart size, serum urea level, positions and types of infarcts, the presence of pulmonary congestion and cardiac dysrhythmia in the initial three days. This simple and convenient CPI could be useful for the objective assessment and stratification of AMI in the Chinese, as well as in many other developing countries in the Asian-Pacific region.

Percutaneous transluminal coronary angioplasty after thrombolytic therapy: a prospective controlled randomized trial

In 162 patients with acute transmural myocardial infarction, combined intravenous and intracoronary thrombolytic therapy with streptokinase was initiated. In vessels that remained occluded, mechanical recanalization was performed with a 3F recanalization catheter (group I, n = 79) or a 4F Grüntzig balloon catheter (group II, n = 83). After reperfusion, intracoronary streptokinase was administered superselectively. After termination of streptokinase infusion, angioplasty was performed only in patients in group II. There was no difference between the groups in relation to sex, age, infarct location, creatine kinase levels and time between onset of symptoms and start of treatment. Initial coronary angiography showed an open vessel in 27 (34%) of 79 patients in group I and 21 (25%) of 83 patients in group II. The final reperfusion rate was 90% (71 of 79) in group I and 86% (71 of 83) in group II. Angioplasty was attempted in 69 of the 71 patients in group II with a success rate of 65% and an occlusion rate of 3%. During the hospital stay, reocclusion occurred in 14 (20%) of 71 patients in group I. After thrombolytic therapy, coronary luminal narrowing in group I was 75 +/- 17% in patients without and 87 +/- 6% in patients with reocclusion (p less than 0.05). In group II, reocclusion was found in 10 (14%) of 71 patients. After angioplasty, the degree of coronary stenosis in group II was reduced from 82 +/- 12 to 51 +/- 30% (p less than 0.001). Reocclusion was found in 3 (7%) of the 45 patients with successful angioplasty and in 7 (32%) of the 22 patients with unsuccessful angioplasty (p less than 0.01). Improvement in regional left ventricular function was observed only in patients from group II with anterior myocardial infarction. In conclusion, by combined medical and mechanical recanalization, the rate of coronary reperfusion can be increased and infarct time shortened, providing the possibility of full revascularization by angioplasty, with improvement of regional wall motion and reduction of the rate of reocclusion.

Sequential intervention procedures after intracoronary thrombolysis; balloon dilatation, bypass surgery, and medical treatment

After successful intracoronary thrombolysis of an acute myocardial infarction in 145 patients subsequent intervention procedures were evaluated. In 48 of 62 patients (43%), percutaneous transluminal coronary angioplasty was performed successfully (success rate 77%), 41 patients (28%) were operated on and 56 patients (39%) were treated only medically. During the hospital phase in the angioplasty group, 4 reinfarctions were noted and 3 repeat angioplasties were required, while 41 of the 48 successfully treated patients (85.4%) remained clinically stable. In the surgical group, one cardiac failure occurred, while 40 patients (97.6%) were without cardiac event. In the medical group, 5 patients died (8.9%), 8 patients (14.3%) had a reinfarction, and 76.8% were clinically stable. During the follow-up period in the surgical group of 6 months 37 patients (90.2%) were clinically stable, all in functional classes I and II. In the angioplasty group 33 patients were stable (68.8%), and in the medical group 26 patients were stable (46.6%). In the whole group of 145 patients the hospital mortality together with that in the 6 months follow-up period was 9.7% with a reinfarction rate of 22.8%.

Combined medical and mechanical recanalization in acute myocardial infarction

A technique of combined medical and mechanical recanalization was employed in 96 patients with acute transmural myocardial infarction. The mean time between onset of symptoms and admission to hospital was 170 +/- 65 min (X +/- SD). After 10 +/- 16 min, 250,000 U streptokinase was administered intravenously for 20 min. Intracoronary thrombolysis was commenced within 38 +/- 14 min. First coronary angiograms demonstrated reperfusion, an open vessel in 25/96 patients (26%). In 15/71 patients (21%) reperfusion occurred during thrombolysis therapy, before mechanical recanalization could be performed. Recanalization was achieved mechanically in 37/71 patients (52%) with occluded coronary vessels. In 8/71 patients (11%) mechanical recanalization failed but the vessel opened during thrombolysis. In 12/96 patients (12%), the coronary vessel remained occluded. Thus, reperfusion could be achieved in 88% of the patients. Reperfusion rate was 76% in the first 38 patients and 95% subsequently. After reperfusion, coronary thrombi were found in 25/96 patients (26%) but dissolved during thrombolysis in 16/25 patients (64%). Peripheral coronary embolism was observed in 3/25 patients (12%). For the whole group, reocclusion occurred in 8/84 patients (10%). By combined medical and mechanical recanalization, the recanalization rate could be increased with low reocclusion rate. Trends showed an improvement in regional and global left ventricular function in patients with anterior myocardial infarction.

The introduction of pulmonary artery pressure and cardiac output measurements in a district general hospital

The problems encountered in introducing a pulmonary artery (PA) pressure and cardiac output (CO) measurement facility in a district general hospital intensive care unit are enumerated. The indications for its use are briefly reviewed.