Unstable angina pectoris: the first half century: natural history, pathophysiology, and treatment

Unstable angina pectoris as a distinct syndrome intermediate between chronic stable angina and acute myocardial infarction was first described about a half century ago. The incidence of death or myocardial infarction rises in the first few months after destabilization of angina. Hemodynamic, scintigraphic, and arteriographic studies in the last 15 years have shown that unstable angina is chiefly due to "dynamic" coronary stenoses, transient reversible limitations in coronary blood flow caused by a complex interaction between coronary vasoconstriction, transient platelet plugging, and transient thrombosis. The trigger for the onset of dynamic coronary stenoses is probably acute changes in coronary arterial morphology in or near atherosclerotic plaques making those areas more thrombogenic. A large fraction of patients with unstable angina restabilize initially with medical management. The role of beta blockers is unclear, but they may protect against development of coronary events for patients with unstable angina similar to that reported for patients with myocardial infarction. Nitrates and calcium blockers are probably superior to beta blockers in restabilization of angina, but protection against coronary events has not yet been demonstrated clearly. Further investigation is needed to distinguish the relative benefits of a two-drug (heart rate-limiting calcium blocker plus nitrates) regimen vs. a three-drug regimen including beta blocker. There is no basis for emergency coronary bypass surgery to prevent myocardial infarction or death. Urgent surgery should be limited to patients who do not stabilize readily with medical therapy. One third or more of the patients who initially restabilize with medical therapy will require coronary revascularization in the year after unstable angina because of severe angina. An antithrombotic regimen of aspirin (or possibly heparin) reduces the incidence of progression to death or myocardial infarction. Two important future directions for research should be promising: development of better antithrombotic regimens other than aspirin alone for protection against coronary events; and improved ability to distinguish the patients who initially respond to medical therapy who are at low risk for later severe angina from those at higher risk.     

Angiographic morphology in unstable angina pectoris

Complex morphology occurs frequently in unstable angina; however, its relation to symptomatic presentation, timing of angiography and hospital outcome has not been investigated. Accordingly, coronary angiography was performed 5 +/- 2 days after qualifying rest pain in 101 consecutive patients presenting with acute coronary insufficiency (n = 67) or crescendo angina (n = 34). Significant coronary artery disease was defined as any greater than or equal to 50% stenosis, and complex morphology as any stenosis with irregularity, overhang or thrombus. Eight of the 67 patients presenting with acute coronary insufficiency later proved to have a myocardial infarction as the qualifying event (creatine kinase twice normal with elevation of MB fraction). There were no myocardial infarctions in the crescendo angina group. Complex morphology occurred in 61% of patients. Thrombus alone occurred in 27% of patients with unstable angina without myocardial infarction, with similar frequencies between the 2 clinical groups. In contrast, intraluminal thrombi were identified in 78% of patients with acute coronary insufficiency who later proved to have a myocardial infarction as the qualifying event. The need for urgent catheterization (less than 48 hours) prompted by recurrent symptoms was associated with the angiographic findings of intraluminal thrombus (46%) and complex morphology (83%). The presence of complex morphology and intracoronary thrombus was associated with a higher incidence of in-hospital cardiac events, i.e., revascularization, myocardial infarction and death, independent of the incidence of multivessel disease.     

Restricted myocardial infarction. Coronary angiographic and ventriculographic findings. Comparison with acute coronary insufficiency and transmural infarction]

The findings at coronary arteriography and ventricular angiography in 52 patients with a restricted myocardial infarct were compared with those of 106 patients with acute coronary insufficiency and 100 with transmural infarcts. Certain features place restricted myocardial infarction in an intermediate category when compared with the two other syndromes. The percentage of coronary occlusions was significantly higher in transmural infarction (23.5%) and in restricted infarction (16.6%) than in acute coronary insufficiency 6.8%). Study of the vessel beyond a tight stenosis (greater than or equal to 75% was particularly effective in clearly separating the three groups. As a result, 63% of patients with coronary insufficiency, 40% of these with restricted infarcts, and only 23% of patients with a transmural infarct could be referred for surgery. Ventricular angiography showed a close relationship between restricted infarction and acute coronary insufficiency because ventricular function appeared normal or subnormal (localised hypokinesia) in 69% and 81% of cases respectively, compared with 4% of cases of transmural infarction. Restricted myocardial infarction appears to resemble coronary insufficiency, but shows elevation of enzymes and often more marked disease of distal vessels.     

Results of emergency bypass operation following percutaneous transluminal coronary angioplasty

Between 1980 and 1988, percutaneous transluminal coronary angioplasty (PTCA) was performed in 1,514 patients. Fifty-five patients (3.6%) underwent emergency coronary bypass surgery because of an acute occlusion of the vessel or a dissection with sustained angina and signs of ischemia on the electrocardiogram. Twenty-five of these 55 patients had a myocardial infarction and 5 patients died, 3 perioperatively, 2 after hospital discharge. The degree of stenosis of the dilated vessel significantly influenced the incidence of infarction, while left ventricular ejection fraction prior to PTCA significantly influenced mortality. Patients who underwent surgery with an occluded vessel experienced myocardial infarction significantly more often (87%) than patients with a patent vessel (24%). The incidence of infarction was 27% when reperfusion of the vessel occluded during PTCA was achieved with a reperfusion catheter, repeated PTCA or intracoronary lysis. The patients' age, presence of unstable angina, left ventricular ejection fraction prior to PTCA, the dilated vessel, the extent of coronary artery disease, collateralization of the dilated vessel, and the time between the onset of the event necessitating bypass surgery and the beginning of extracorporeal circulation were found to have no influence on the incidence of infarction. Patients who died had a significantly lower ejection fraction before PTCA than survivors and all patients who died had experienced a large perioperative myocardial infarction.     

Coronary angioplasty in unstable angina. Immediate and short-term results

We report the results of percutaneous transluminal coronary angioplasty (PTCA) in 67 consecutive patients with unstable angina. Twenty patients had new onset (less than 2 months) angina, 33 patients had crescendo angina and 14 had early postinfarction angina. Fifty-one patients had one-vessel disease, 12 patients had two-vessel disease and two patients had three-vessel disease; two patients had a stenosis of a venous graft. In cases with multivessel disease, we performed only the dilatation of the ischaemia-related vessel identified by morphologic features of coronary lesion and electrocardiographic changes during chest pain. The procedure was successful in 54 cases (80.6%). Seven patients (10.4%) had major complications. Emergency coronary artery bypass graft surgery was performed in 6 cases (8.9%) because of occlusion of the left anterior descending artery; despite emergency operation one patient died and two patients sustained a myocardial infarction. One patient had occlusion of the right coronary artery and inferior myocardial infarction. In all patients in whom angioplasty was successful unstable angina disappeared. At 6 months follow-up there were no infarctions or deaths but 14 of 42 patients (33%) had recurrent angina. Restenosis occurred in 16 of 33 patients (48%) who had repeat coronary angiography. Four patients with recurrence of unstable angina had repeat angioplasty; it was successful in 3 cases. One patient died of refractory cardiac arrest. The mortality rate of 71 procedures performed in 67 patients was 2.8% (2/71) and the overall myocardial infarction rate was 4.2% (3/71).(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardiac pain at rest. Management and follow-up of 100 consecutive cases.

One hundred consecutive patients, admitted to the coronary care unit with cardiac pain at rest but no evidence of recent myocardial infarction have been followed up for nine to 26 (mean 14) months. They were treated initially with bed rest, beta-adrenergic blockade, and nitrates. In 54 patients pain subsided within 24 hours. Coronary angiography was carried out in 46. Thirty-five had coronary artery lesions and three had spasm in normal coronary arteries. One had hypertrophic cardiomyopathy and seven had normal findings. Seventeen patients with previous angina and severe coronary disease were operated on, with one death and one perioperative infarction; two died late, 12 were symptom free, and two had angina. Seven of 18 patients treated medically had recurrent angina and underwent operation. Of the 11 unoperated patients, one died, three had angina, and seven were symptom free. Two of the eight patients who were not catheterised developed infarction, four had angina, and three were symptom free. Recurrent pain continued for more than 24 hours in 46 patients, and all underwent angiography. Forty-three had coronary artery disease and 34 underwent early bypass surgery; there were two operative deaths and three perioperative infarctions. Twenty-six symptom free at follow-up. Of the nine unoperated patients with coronary disease, four developed infarction, two were operated on for recurrent angina, two were symptom free, and one had mild angina. Optimal management of patients with pain at rest can be determined only with knowledge of the coronary artery anatomy and of left ventricular function. Many respond initially to intensive medical treatment and coronary angiography can be performed electively. In those with continuing pain, urgent angiography is required and can be done safely.     

Acute myocardial infarction and ischemic injury during surgery for coronary artery disease.

The incidence of myocardial infarction, acute ischemic injury, and associated serum enzyme abnormalities has been evaluated in four operations involving the coronary circulation. The highest incidence of infarction was associated with internal mammary implantation (Vineberg procedure). There was no significant difference in the incidence of infarction, ischemic injury, or abnormal enzyme levels between patients with stable angina and those with unstable angina who had vein bypass surgery. In operations involving combined vein bypass grafting and valve replacement surgery, the incidence of abnormal serum enzyme elevations was higher than in any other procedure. The incidence of infarction and acute ischemic injury in combined operations was similar to that in other procedures but this may have been due to the difficulty in the ECG diagnosis of infarction in this group of patients, most of whom had abnormal preoperative ECGs.     

Clinical experience with left main coronary artery stenosis.

We report the clinical features and the results of investigation and surgery in 20 patients with significant left main coronary artery stenosis. All had moderate to severe angina; 8 had pain at rest. Three had dyspnoea as a major symptom. The electrocardiogram was abnormal in 17, with evidence of previous myocardial infarction in 10. Of the 11 patients exercised, 8 developed chest pain. Nine patients had a normal left ventriculogram. At coronary angiography all patients had major disease elsewhere in addition to the left main coronary artery stenosis. There were no deaths or major complications associated with this investigation. One patient was unsuitable for surgery because of diffuse left ventricular hypokinesia, one had a fatal myocardial infarction while awaiting operation, and there was one preoperative death. Sixteen of the 17 surgical survivors are free from angina. There has been a significant improvement in the maximum exercise capacity in the 10 patients who had pre- and postoperative exercise tests.     

Clinical experience with left main coronary artery stenosis.

We report the clinical features and the results of investigation and surgery in 20 patients with significant left main coronary artery stenosis. All had moderate to severe angina; 8 had pain at rest. Three had dyspnoea as a major symptom. The electrocardiogram was abnormal in 17, with evidence of previous myocardial infarction in 10. Of the 11 patients exercised, 8 developed chest pain. Nine patients had a normal left ventriculogram. At coronary angiography all patients had major disease elsewhere in addition to the left main coronary artery stenosis. There were no deaths or major complications associated with this investigation. One patient was unsuitable for surgery because of diffuse left ventricular hypokinesia, one had a fatal myocardial infarction while awaiting operation, and there was one preoperative death. Sixteen of the 17 surgical survivors are free from angina. There has been a significant improvement in the maximum exercise capacity in the 10 patients who had pre- and postoperative exercise tests.     

Role of intracoronary thrombus in acute complications during percutaneous transluminal coronary angioplasty

Coronary angiograms from 2,372 consecutive patients who underwent percutaneous transluminal coronary angioplasty (PTCA) were retrospectively reviewed for the presence of intracoronary thrombus (ICT) before dilatation. Patients with evolving acute myocardial infarction and those receiving thrombolytic therapy were excluded from analysis. Coronary artery thrombus was present in 126 patients (6%) (group 1). When compared to 2,246 patients (group 2) without ICT, group 1 had a higher incidence of unstable angina, 74% vs. 66% (less than 0.06), previous myocardial infarction, 59% vs. 37% (P less than .0001), and history of a recent myocardial infarction, 28% vs. 9% (P less than .0001). Patients with predilatation intracoronary thrombus had a higher risk for acute occlusion, 6% vs. 2% (P less than .002); however, the incidence of emergency coronary bypass surgery and myocardial infarction was similar in both groups. Therefore, the presence of predilatation intracoronary thrombus heralds an increased risk of acute occlusion, but not myocardial infarction or emergency coronary artery bypass surgery.     

Short term results of percutaneous transluminal coronary angioplasty with the monorail technique: experience in the first 1000 patients.

The monorail technique allows monitoring of all steps of the coronary angioplasty procedure by high quality coronary angiography; easy, rapid, and safe recrossing and redilatation of the lesion if necessary; and stepwise dilatation of a stenosis with sequential increase of size of balloons. Transstenotic pressure differences cannot, however, be measured through the narrow shaft of the standard monorail balloon catheter. The monorail technique was used in 1014 patients (820 men, 194 women; mean age 57.8 years (range 24 to 84]. The indication for coronary angioplasty was stable angina in 52%, unstable angina in 40%, and acute myocardial infarction in 8%. Single vessel coronary angioplasty was attempted in 78%, multilesion coronary angioplasty in 11%, and multivessel coronary angioplasty in 11%. Angiographic success (reduction of stenosis to less than 50% of the luminal diameter) of all attempted lesions was achieved in 93%. The technique was clinically successful--that is, angiographic success of all attempted lesions, no occurrence of a major complication (death, myocardial infarction, acute bypass surgery), and improvement of symptoms--in 92% and partially successful in 1.3%. The clinical success rates were similar for stable angina (91%) and unstable angina (94%), but were somewhat lower for acute myocardial infarction (88%). Failure without major complication occurred in 3.4% of the patients. Failure with a major complication occurred in 3.3% (death 0.3%, myocardial infarction 2.4%, and acute bypass surgery 2.3%). The total major complication rate was higher in unstable angina (4.2%) than in stable angina (3.0%). These results indicate that the monorail technique can be applied safely and effectively for coronary angioplasty of patients with stable angina, unstable angina, and acute myocardial infarction.     

Triple vessel coronary angioplasty: acute outcome and long-term results

Triple vessel coronary angioplasty, defined as angioplasty of one or more lesions in each of the three major coronary arteries (left anterior descending, left circumflex, right coronary artery) was performed in 50 (11%) of 469 patients who had angioplasty of multiple vessels. There were 32 men and 18 women with a mean age of 56 years. All 50 patients had severe three vessel coronary disease and represent approximately 5% of patients with three vessel disease who had revascularization in this institution; 8 (16%) had previous coronary bypass surgery, and 23 (46%) had previous myocardial infarction. Unstable angina was present in 33 patients (66%) and 96% had Canadian Heart Association class III or IV angina; mean left ventricular ejection fraction was 57 +/- 11%. Angioplasty was performed in 176 vessels (3.5 vessels per patient, range 3 to 6) and in 250 lesions (5 lesions per patient, range 3 to 9); angiographic success was achieved in 240 lesions (96%) and 166 vessels (94%). Success in all vessels attempted was achieved in 40 (80%) of the 50 patients. Clinical success (angiographic success associated with clinical improvement) was obtained in all 50 patients in whom triple vessel angioplasty was performed; none of them required urgent bypass surgery and 5 patients (10%) had a non-Q wave myocardial infarction. In four other patients triple vessel angioplasty was planned but not performed because of failure to dilate the primary vessel; urgent bypass surgery was required in one of these, who developed a Q wave infarction. Thus, overall clinical success in 54 patients was 93%; the incidence rate of myocardial infarction was 11%, and that of urgent surgery 1.8%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Preinfarct stenocardia and acute myocardial infarct from the viewpoint of modern coronary surgery]

The results of aorto-coronary shunting in 36 patients with preinfarction angina and of urgent direct myocardial revascularization in 17 patients with acute myocardial infarction are presented. The surgical mortality comprised 28% in the group of patients with preinfarction angina. Twenty-two patients were followed-up for 8 months to 4 years. Good results were obtained in 9 patients, satisfactory--in 7, unsatisfactory--in 4. One patient died of cardiac insufficiency 1 1/2 year after surgery. The diagnosis of preinfarction angina is a direct indication for urgent coronary angiography and aorto-coronary shunting in case suitable coronary arteries are available for anastomosing. The indications for urgent revascularization of the myocardium in cases of infarction included the inefficacy of drug therapy within 2-3 hours of its onset, an unarrested pulmonary oedema and cardiogenic shock in cases of localized proximal occlusion of the coronaries revealed by elective or urgent coronary angiography. Four patients were operated on in the state of cardiogenic shock (one of them after reversing the state of clinical death), and two patients were operated on with pulmonary oedema. All these patients (with the exception of the one with pulmonary oedema) recovered. Four patients died. The follow-up covered a period of 9 months to 3 years. Good results were obtained in 4 patients, satisfactory--in 3, unsatisfactory--in 4. No late mortality cases were observed. The obtained results permit to analyse the preinfarction angina and acute myocardial infarction from the standpoint of modern coronary surgery.     

Unstable angina--clinical manifestations and prognosis of 74 medically-treated patients

Seventy-four patients with unstable angina are reviewed. A rather high incidence (65%) of a changing pattern syndrome was observed in the study group. A history of prior myocardial infarction was obtained in 22 patients (30%). Fifty-seven patients (77%) were investigated using coronary angiography: 15 did not have any significant occlusive disease but are included in this study; single vessel disease was present in 20, double in 8 and triple in 14. Ten patients (13.5%) had myocardial infarcts which had occurred between 48 hours and 3 months after admission, and no patients died during this period. Patients who on admission had resting angina of new onset were more likely to have a worse short-term prognosis. Four patients underwent coronary bypass surgery in the first year of the follow-up period because of unsuccessful medical treatment. Six patients died within the first 4 years. Of the 6 deaths, 5 had triple vessel disease and one did not have any significant coronary stenosis. Mortality rate at 2 years was 2.7% and at 4 years 10.3%. This low mortality is probably attributable to a low incidence of 2- or 3-vessel disease.     

Follow up results of treatment of unstable angina by coronary angioplasty.

Eighty nine of 327 consecutive patients undergoing coronary angioplasty at a centre had unstable angina--defined as either a worsening of the frequency or the severity of chest pain or severe episodes of chest pain at rest with no evidence of acute myocardial infarction. Multivessel disease was present in 31 of these patients. Two or more vessels were dilated in the same procedure in one fifth of the patients. Primary success was obtained in 80 (90%) patients. Acute myocardial infarction was a complication in four (5%) patients, including two of four patients who needed emergency coronary bypass grafting. Follow up coronary angiography at a mean (SD) of 10 (6) months in 57 patients showed restenosis in 21 (37%): of these, 13 patients had repeat coronary angioplasty and three had elective coronary bypass grafting. All patients in whom angioplasty was initially successful were followed up for 10 (6) months after the last angioplasty procedure. There were no deaths. One patient had sustained a myocardial infarction unrelated to the dilated vessel. Clinically, 74 patients improved by at least one New York Heart Association class and 40 (50%) were symptom free and with no signs or symptoms of myocardial ischaemia on a stress test. Coronary angioplasty offers long term symptomatic improvement at an acceptable risk in the majority of patients with unstable angina.     

Role of coronary artery spasm in ischemic heart disease. Therapeutic implications

The term coronary artery spasm should not be used interchangeably with the specific clinical syndrome "variant angina" since it does occur in other acute and chronic ischemic heart disease syndromes. The term coronary artery spasm should not be applied to patients with ischemic heart disease unless there is clinical, angiographic, and physiologic evidence of its presence. The diagnosis of coronary artery spasm is confirmed by angiography, i.e. change in caliber of the coronary arteries plus evidence of ischemia. Probable diagnosis is in patients who have the syndrome of variant angina, i.e. rest angina associated with ST segment elevation on the electrocardiogram. One can be highly suspicious that the spasm is at work in patients who have rest angina, especially those with unstable angina. One can be suspicious of patients who have variable effort angina or walk-through angina. Coronary artery spasm is a possibility in patients with an acute myocardial infarction or acute re-infarction and is also possible that sudden death in patients with normal coronary arteries can be related to coronary artery spasm. Coronary artery spasm is the usual cause of myocardial ischemia in patients with rest angina without effort angina. This has also commonly been documented in patients with rest and effort angina. There are isolated reports suggesting that patients with effort angina pectoris also develop coronary artery spasm. Coronary artery spasm has been documented to occur in association with acute myocardial infarction. Whether coronary artery spasm is the cause or the result of myocardial infarction has not been determined at this time. However, the recent combined use of intracoronary nitroglycerin and intracoronary streptokinase in patients with acute myocardial infarction has shown reversal of totally obstructed arteries and suggests the relationship between coronary artery disease, coronary artery spasm, and in situ coronary thrombosis. The incidence of sudden death in patients with documented coronary artery spasm is unknown. But, since complete heart block and/or ventricular tachycardia occur during episodes of coronary artery spasm, it is not unreasonable to assume that some patients have died as a result of these rhythm disturbances. The prognosis of patients with coronary artery spasm seems to depend on the presence or absence of severe coronary atherosclerosis, i.e. those with severe disease have a worse prognosis. Current therapy of patients with coronary artery spasm involves the use of nitrates and calcium antagonists.(ABSTRACT TRUNCATED AT 400 WORDS)     

微量白蛋白尿对非糖尿病急性心肌梗死预后的意义

目的：探讨微量白蛋白尿（MA）与非糖尿病急性心肌梗死（NDM－AMI）患者预后的关系。方法：收集1996年10月－2001年5月期间肾功能处于代偿期的NDM－AMI住院病人43例，分MA阳性组和MA阴性组，对入院后心肌梗死面积大小（心电图、心肌酶谱分析）、冠状动脉造影结果、AMI后3月心内绞痛、再发心肌梗死，心衰发生率及死亡率进行统计学分析。结果：NDM－AMI患者MA阳性占53．49％，冠状动脉造影提示MA阳性组冠状动脉粥样硬化病变程度较MA阴性组广泛和严重；EKG和血清心肌酶谱显示MA阳性组心肌梗死面积大于MA阴性组（P＜0．05）；两组AMI后3月内心绞痛、再发心肌梗死、心衰发生率和死亡率具有显著性差异（P＜0．01）。结论：MA阳性提示NMD－AMI患者体内广泛性血管病变，且近期预后不良。     

Value of exercise stress test, radionuclide angiography and coronary angiography in predicting new coronary events in asymptomatic patients after a first episode of myocardial infarction.

One-hundred-and-fifty-five consecutive symptom-free patients underwent maximal treadmill exercise testing, rest and stress radionuclide angiography at least two months after an uncomplicated acute myocardial infarction; of these, 90 underwent coronary angiography. All patients were followed-up for a mean of 32 +/- 13 months regarding the prediction of hard (death and reinfarction) and soft (angina and coronary surgery) coronary events. The specificity, sensitivity, positive and negative predictive value of exercise stress test were 47%, 76% and 41% for any coronary events; none of the patients who incurred a hard coronary event showed ischemia during electrocardiographic exercise tests. Sensitivity, specificity and positive predictive value for failure to increase the ejection fraction of at least 5% were 60%, 45% and 30% for any coronary event and 25%, 49% and 2% for any hard coronary event. The presence of multivessel disease at coronary angiography showed a sensitivity of 62% for any coronary event and of 67% for hard coronary events; specificities were 66% and 57%, and predictive values were 52% and 10%, respectively. It is concluded that electrocardiographic exercise testing, radionuclide angiography and coronary angiography are not helpful two months after an episode of uncomplicated myocardial infarction in order to identify patients who will suffer a new coronary event.     

Coronary revascularization at the acute phase of myocardial infarction. Short and median-term survival of 359 patients. Multicenter study

Three hundred and fifty nine consecutive patients from 4 different French centres who underwent attempted early coronary revascularisation during the acute phase of myocardial infarction by intracoronary thrombolysis (309 cases) intravenous thrombolysis (26 cases) and transluminal angioplasty (24 cases) were reviewed to evaluate the short and medium term results of these non-surgical techniques. Three groups of patients were identified from the results of initial and secondary coronary angiography: 1) deaths during the procedure (1.9%), 2) successes, with immediate and stable revascularisation (65%), 3) failures, also including initial successes with secondary reocclusion (33.1%). The global mortality at one month was 10.9%. This was significantly lower after revascularisation (p less than 0.001): 4.7% in patients with successful procedures and 17.6% in the others. The one year survival rate was also significantly higher in patients successful revascularisation (93 +/- 4% vs 75 +/- 8%, p less than 0.001). There were more recurrent infarctions and residual angina in patients with successful early coronary revascularisation: 7.7% and 12% respectively vs 4.2% and 8.4% respectively in the other patient group. In the successful group, 200 patients (86%) had one or more stenoses greater than 70% narrowing after coronary revascularisation. The recurrent infarction rate in the 94 patients treated medically was 9% and 17% had residual angina compared to 6% and 10% respectively in the 106 patients referred for coronary bypass surgery or undergoing complementary angioplasty. Three conclusions may be drawn from this non-randomised study of coronary revascularisation during the acute phase of myocardial infarction: attempts at coronary revascularisation do not aggravate the immediate prognosis of myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characteristics and outcome of patients with ST‐elevation infarction in relation to whether they received thrombolysis or underwent acute coronary angiography: Are we selecting the right patients for coronary angiography?

BACKGROUND: During the last decade, there has been an on-going debate with regard to whether percutaneous coronary intervention (PCI) or thrombolysis should be preferred in patients with ST-elevation acute myocardial infarction (AMI). Some studies clearly advocate PCI, while others do not. HYPOTHESIS: The study aimed to describe the characteristics and to evaluate outcome of patients with suspected ST-elevation or left bundle-branch block infarction in relation to whether they received thrombolysis or had an acute coronary angiography aiming at angioplasty. METHODS: The study included all patients admitted to Sahlgrenska University Hospital in G?teborg, Sweden, with suspected acute myocardial infarction who, during 1995-1999, had ST-elevation or left bundle-branch block on admission electrocardiogram (ECG) requiring either thrombolysis or acute coronary angiography. A retrospective evaluation with a follow-up of 1 year after the intervention was made. RESULTS: In all, 413 patients had thrombolytic treatment and 400 had acute coronary angiography. The patients who received thrombolysis were older (mean age 70.3 vs. 64.1 years). Mortality during 1 year of follow-up was 20.9% in the thrombolysis group and 16.6% in the angiography group (p = 0.12). Among patients in whom acute coronary angiography was performed, only 85% underwent acute percutaneous coronary intervention (PCI). There was a mortality of 12.1 vs. 41.7% among those who did not undergo acute PCI. Development of reinfarction, stroke, and requirement of rehospitalization was similar regardless of type of initial intervention. The thrombolysis group more frequently required new coronary angiography (36.9 vs. 20.6%; p<0.0001) and new PCI (17.8 vs. 11.9%; p = 0.01). Despite this, after 1 year symptoms of angina pectoris were observed in 27% of patients in the thrombolysis group and in only 14% of those in the angiography group (p = 0.0002). CONCLUSION: In a Swedish university hospital with a high volume of coronary angioplasty procedures, we found no significant difference in mortality between patients who had thrombolysis and those who underwent acute coronary angiography. However, requirement of revascularization and symptoms of angina pectoris 1 year later was considerably less frequent in those who had undergone acute coronary angiography. However, distribution of baseline characteristics was skewed and efforts should be focused on the selection of patients for the different reperfusion strategies.