Does in-hospital ventricular fibrillation affect prognosis after myocardial infarction?

AIM: The aim of this study was to estimate the prognostic informationto be gained from ventricular fibrillation in patients withmyocardial infarction. METHODS AND RESULTS: We studied 4259 consecutive patients with myocardial infarctionadmitted to one centre in 1977–1988. Five hundred andtwenty-eight (12·4%) of the patients had ventricularfibrillation in hospital. The following risk factors were includedin multivariate models to estimate their importance for 30-dayand long-term (median 7 year) prognosis: age, gender, ventricularfibrillation, congestive heart failure, pulmonary oedema, cardiogenicshock, other cardiac arrest and atrial fibrillation. We foundthat the odds ratio for death on days 6–30 was 6·34(3·55–11·30, 95% confidence limits, P<0·001)for patients with primary ventricular fibrillation (withoutheart failure) and 4·06 (2·68–6·14,p<0·001) for patients with ventricular fibrillationsecondary to heart failure compared to patients without ventricularfibrillation. For patients surviving more than 30 days, relativerisk of death in those with ventricular fibrillation was 1·11(95% confidence interval 0·93–1·34, P=0·26).Logistic regression analysis of relative risk associated withventricular fibrillation in time intervals, indicated that theimportance of ventricular fibrillation for risk of death wasexhausted during the initial 60 days after infarction. CONCLUSION: Ventricular fibrillation is associated with an independent increasedrisk of death within 0–60 days after infarction. Afterthis period, the prognosis in survivors of ventricular fibrillationdoes not differ significantly from patients without ventricularfibrillation.     

Pre-hospital and hospital time delays in thrombolytic treatment in patients with suspected acute myocardial infarction: Analysis of data from the EMIP study

OBJECTIVES: To compare the components of the time delay involved in pre-hospitaland hospital thrombolytic therapy in patients presenting withsuspected acute myocardial infarction. MATERIAL AND METHODS: From October 1988 to January 1992 a total of 198 mobile emergencyunits in 15 European countries and Canada randomized 5469 patientsto receive either pre-hospital thrombolytic treatment, followedby placebo in hospital (pre-hospital group), or pre-hospitalplacebo, followed by thrombolytic treatment in hospital (hospitalgroup) in the European Myocardial Infarction Project trial.We performed a post hoc analysis of these data to correlatecomponents of the interval between symptom onset and treatmentwith baseline patient characteristics. RESULTS: The delay between onset of symptoms and calling for an ambulancewas significantly longer for female patients (P0·0001),older patients (>65 years old; P=0·0001), those whohad experienced pain within the previous 24 h (P=0·0001),and those with pulmonary oedema (P=0·04). This delaywas significantly shorter in patients with previous myocardialinfarction (P=0·02), those with ventricular fibrillation(P=0·0001), and those in shock (P0·0001). Thedelay between the two injections was significantly longer forolder patients (>65 years old; P=0·02), those withprevious myocardial infarction (P=0·03), and those inshock (P=0·003). CONCLUSIONS: Action undertaken to reduce delays between symptom onset andtreatment should focus on modifiable factors such as patientswho are likely to be late callers, i.e. women and those over65 years of age.     

Early ventricular fibrillation in patients with acute myocardial infarction: correlation with coronary angiographic findings

To define coronary angiographic characteristics of patientsexperiencing early primary ventricular fibrillation (VF) inthe acute phase of myocardial infarction we studied 266 consecutivepatients without clinical evidence of heart failure. Twenty-sixpatients (group 1) experienced early (< 12 h from the onsetof symptoms of myocardial infarction) primary VF whereas 240patients (group 2) with the same clinical characteristics servedas an appropriately matched cohort. All patients were catheterizedbefore or soon after hospital discharge (1 to 8 weeks afterthe acute event). There was no significant difference in left ventricular ejectionfraction between the two groups of patients (39.6±6%vs 36.9±8%, P = ns). Patients with early VF had a significantlygreater number of diseased vessels than those without VF (3.38±1.05vs 2.03±1.25. P <0.001) and a higher coronary arteriographicGensini score (29.31±4.80 vs 20.16±4.14, P <0.001).The left anterior descending coronary artery was identifiedas the infarct-related vessel in 53.6% of group 1 vs 44.5% ofgroup 2 patients (P <0.05). The mean maximal serum creatinekinase values were not significantly different (1897±1062vs 1426 ±839 IU.l–1, P=ns) between the two groups. These data indicate that patients with early primary VF in thesetting of acute myocardial infarction may have more extensivecoronary artery disease than similar patients without VF. Aworse prognosis could be anticipated for these patients on thebasis of worse coronary anatomy. A more aggressive therapeuticapproach with routine coronary angiography before hospital dischargecould reasonably be justified for patients with early primaryVF complicating acute myocardial infarction.     

Invasive reperfusion study II. Multicentre European randomized trial of anistreplase vs streptokinase in acute myocardial infarction

IRS II (Invasive reperfusion study II) was a multicentre randomizedtrial comparing the efficacy of a 2–5-min 30 U anistreplaseintravenous injection with a 1 500 000 U 60-min streptokinase(SK) intravenous infusion in acute myocardial infarction. 116patients were randomized within 6 h of onset of symptoms. Earlycoronary patency was assessable in 107 patients by coronaryangiogram performed 102 min after thrombolytic treatment (range:30–297 min) in the anistreplase group and 93 min (range:22–330 min) in the SK group. The early coronary patencyrate was significantly higher in the anistreplase group thanin the SK group: respectively, 70% (38/54) and 51% (27/53),P<0.05. Fifty patients had assessable coronary angiogramsat 90 min and 24 h. The 24-h patency rate was 92.3% (24/26)in the anistreplase group vs 87.5% (21/24) in the SK group.No early reocclusion occurred in the anistreplase group vs 15.4%(2/13) in the SK group (NS). Fibrinogen fell to 13.2 ±19.8%on anistreplase vs 9.4 ±10.3% on SK (NS). Bleeding complicationsoccurred in 12% (7/58) of treated patients in the anistreplasegroup vs 20.7% (13/58) in the SK group (NS). Two cerebrovascularaccidents occurred after thrombolytic treatment with anistreplase(3.4%) vs one after SK (1.7%) (NS). Thus, anistreplase is moreeffective than intravenous SK and easier to administer.     

Pre-hospital thrombolytic therapy with either alteplase or streptokinase: Practical applications, complications and long-term results in 529 patients

OBJECTIVE: To assess the practical application, safety and long-term outcomeof pre-hospital thrombolytic intervention with either alteplaseor streptokinase in patients with extensive myocardial infarction. DESIGN: Prospective study. SUBJECTS: Patients with chest pain of more than 30 min duration, presentingwithin 6 h of symptom onset and with electrocardiographic evidenceof extensive evolving myocardial infarction. METHODS: Eligibility of patients was established by the general practitioneror the ambulance nurse using a standardized questionnaire with(contra-) indications for thrombolytic therapy. ComputerizedECG was recorded by ambulance nurses. In the presence of extensiveST segment elevation (sum ST deviation of at least 1.0 m V),eligible patients received either 100 mg alteplase (n=246) or50 mg alteplase in the ambulance followed by 0.75 x 10⁶ IE streptokinasein hospital (n=90), or 1.5 x 10⁶ IE streptokinase intravenously(n=193). MAIN OUTCOME MEASUREMENTS: Death and life-threatening complications (ventricular fibrillation,cardiac arrest) and side effects (hypotension, allergic reactions)during transportation to hospital and in the first 24 h followinghospitalization, and survival up to 5 years follow-up. RESULTS: From 1988–1993, 529 patients received thrombolytic treatmentinitiated pre-hospital. The time gained by pre-hospital administrationof thrombolysis amounted to 50 min. The rate of complicationsduring transportation and during the first 24 h after hospitalizationwas low. Hospital mortality was 2% and 1-year mortality 3%.Cumulative survival at 5 years was 92%. This was superior tothe 84% 5-year survival observed in a matched group of 239 patientswith similar baseline characteristics treated with alteplasein hospital. CONCLUSIONS: Pre-hospital administration of either alteplase or streptokinaseis feasible and safe and results in significant time gain. Thelong-term prognosis is excellent in spite of extensive evolvingmyocardial infarction upon admission.     

The 60 Minutes Myocardial Infarction Project. Characteristics on admission and clinical outcome in patients with reinfarction compared to patients with a first infarction

Purpose The purpose of the study was to evaluate parameters that characterizepatients with myocardial reinfarction as compared to patientswith a first infarction in clinical practice, and possibly todetermine their clinical outcome. Methods The 60 Minutes Myocardial Infarction Project is a German multicentreprospective observational study in which 136 hospitals are participating.Fourteen thousand, nine hundred and eighty consecutive patientswith acute Q wave myocardial infarction were included from July1992 to September 1994. Results Out of these 14980 patients, there were 2854 (19%) with reinfarctionand 12126 (81%) with a first infarction. Patients with a reinfarctionarrived at the hospital 24min earlier than patients with a firstinfarction (pre-hospital delay 156 vs 180min;P<0·001);the door-to-needle time with reinfarction was longer (38 vs30min;P<0·001); however, patients with reinfarctionwere older (69 vs 66 years;P<0·001), had a lower rateof a diagnostic first ECG (54 vs 71%;P<0·001) andreceived thrombolytic therapy less frequently than patientswith a first infarction (46 vs 52%;P<0·001). A lownumber of patients received primary PTCA (n=205) since onlya few hospitals offered a primary PTCA service at the time thestudy was performed. In patients with reinfarction, there weremore reasons as to why thrombolytic therapy was not given (24vs 21%;P<0·001). Left bundle branch block occurredmore frequently in patients with reinfarction (15 vs 8%;P<0·001).The intra-hospital course in patients with reinfarction wasassociated with an increase of complications and intra-hospitaldeath (23 vs 15%;P<0·001). Conclusions Although reinfarction patients arrived earlier at hospital thanpatients with a first infarction, the former received thrombolytictherapy less frequently than the latter. Patients with reinfarctionwere older, more frequently had a non-diagnostic ECG on admissionand had a higher rate of contraindications against thrombolytictherapy.     

Long-term prognosis (survival) of myocardial infarct patients after clinical death as a result of ventricular fibrillation (results of a 16-year study)

The occurrence of primary ventricular fibrillation in the acute period of myocardial infarction has little if any effect on the late survival rate of either the entire group of patients or different age subgroups. The primary fibrillation of the ventricle has no effect on the survival of patients with the first and recurrent myocardial infarction who have had repeated episodes of clinical death. The survival rate of patients resuscitated in the hospital does not differ from that seen in patients resuscitated at the pre-hospital stage. The secondary ventricular fibrillation reduces survival very markedly. Recent years have seen an increase in the survival rate following ventricular fibrillation.     

Are the various thrombolytic agents equally effective in the treatment of acute transmural myocardial infarction?

While it is no longer possible to imagine the treatment of an acute transmural myocardial infarction without the use of thrombolytic agents, some discussion still exists as to the choice of the thrombolytic agent. Our study concerns a group of 160 patients with an acute transmural myocardial infarction, 60 of whom were treated with anistreplase, 52 with streptokinase and 48 with alteplase. Statistically, the administration of anistreplase was associated with a significantly higher frequency of ventricular arrhythmias in comparison to the other thrombolytic agents, whereas after subsequent coronary angiography, the anistreplase group revealed a significantly lower number of completely occluded coronary arteries. The data from this study demonstrate that anistreplase is a very valuable thrombolytic agent. It may even be more effective than streptokinase and alteplase in the treatment of acute myocardial infarction when the patency of the coronary arteries 1 month after the acute coronary event is considered the primary endpoint.     

Pre-hospital thrombolytic therapy with either alteplase or streptokinase: Practical applications, complications and long-term results in 529 patients

OBJECTIVE: To assess the practical application, safety and long-term outcomeof pre-hospital thrombolytic intervention with either alteplaseor streptokinase in patients with extensive myocardial infarction. DESIGN: Prospective study. SUBJECTS: Patients with chest pain of more than 30 min duration, presentingwithin 6 h of symptom onset and with electrocardiographic evidenceof extensive evolving myocardial infarction. METHODS: Eligibility of patients was established by the general practitioneror the ambulance nurse using a standardized questionnaire with(contra-) indications for thrombolytic therapy. ComputerizedECG was recorded by ambulance nurses. In the presence of extensiveST segment elevation (sum ST deviation of at least 1·0m V), eligible patients received either 100 mg alteplase (n=246)or 50 mg alteplase in the ambulance followed by 0·75x 10⁶ IE streptokinase in hospital (n=90), or 1·5 x 10⁶IE streptokinase intravenously (n=193). MAIN OUTCOME MEASUREMENTS: Death and life-threatening complications (ventricular fibrillation,cardiac arrest) and side effects (hypotension, allergic reactions)during transportation to hospital and in the first 24 h followinghospitalization, and survival up to 5 years follow-up. RESULTS: From 1988–1993, 529 patients received thrombolytic treatmentinitiated pre-hospital. The time gained by pre-hospital administrationof thrombolysis amounted to 50 min. The rate of complicationsduring transportation and during the first 24 h after hospitalizationwas low. Hospital mortality was 2% and 1-year mortality 3%.Cumulative survival at 5 years was 92%. This was superior tothe 84% 5-year survival observed in a matched group of 239 patientswith similar baseline characteristics treated with alteplasein hospital. CONCLUSIONS: Pre-hospital administration of either alteplase or streptokinaseis feasible and safe and results in significant time gain. Thelong-term prognosis is excellent in spite of extensive evolvingmyocardial infarction upon admission.     

Use of left ventricular function as an end point of thrombolytic therapy.

In recent acute myocardial infarction, early reperfusion of the infarct-related artery by intracoronary or intravenous thrombolytic therapy induces a significant limitation of infarct size, provided reperfusion occurs within a time frame that myocardial salvage can still be expected. Limitation of infarct size reduces scar tissue formation, aneurysm formation, infarct zone expansion, left ventricular volume enlargement, and eventually results in higher left ventricular ejection fraction. Infarct size limitation and left ventricular function preservation occur with all thrombolytic agents currently in clinical use: streptokinase, alteplase and, more recently, anistreplase. When anistreplase is compared with conventional heparin therapy, a 31% reduction in infarct size is found (estimated from single photon emission computed tomography, or SPECT). This translates into a significant preservation of left ventricular ejection fraction as observed in anistreplase-treated patients compared with heparin-treated patients (0.53 +/- 0.13 vs 0.47 +/- 0.12, p less than 0.002). In comparative trials of 2 thrombolytic agents, anistreplase was demonstrated to be as efficient as alteplase on left ventricular ejection fraction preservation and infarct size limitation.     

Changes in the surface electrocardiogram during the onset of spontaneous ventricular fibrillation in man

The aim of this study was to quantify electrocardiographic changesduring the onset and early stages of ventricular fibrillation.Thirty recordings of ventricular fibrillation (mean duration57 s, range 24–160 s) were obtained from 23. CoronaryCare Unit patients. Each recording was investigated using frequencyanalysis on 1 s epochs of data. A significant rise in the meandominant frequency of ventricular fibrillation from 3·9Hz (SD 0·8 Hz) to 5·9 Hz (SD 1·0 Hz) wasobserved between 1 s and 30 s (P<0·00l). At the sametime, the width of the dominant peak decreased signicantly (P<0·001)and the height of higher frequency harmonics fell (P<0·01).There was no signficant change in peak height as ventricularfibrillation evolved. This study shows that the electrocardiogramretains periodic characteristics during the first 30 s of ventricularfibrillation and that these periodic characteristics becomeconcentrated in a progressively narrower band off requencses.These findings would suggest that during the early stages ofventricular fibrillation myocardial activation is both acceleratingand coherent, rather than incoherent as has been traditionallybelieved.     

Multicentre randomized trial comparing transport to primary angioplasty vs immediate thrombolysis vs combined strategy for patients with acute myocardial infarction presenting to a community hospital without a catheterization laboratory. The PRAGUE study.

BACKGROUND: Primary coronary angioplasty is an effective reperfusion strategy in acute myocardial infarction. However, its availability is limited, and transporting patients to an angioplasty centre in the acute phase of myocardial infarction has not yet been proved safe. METHODS: The PRAGUE study (PRimary Angioplasty in patients transferred from General community hospitals to specialized PTCA Units with or without Emergency thrombolysis) compared three reperfusion strategies in patients with acute myocardial infarction, presenting within 6 h of symptom onset at community hospitals without a catheterization laboratory: group A - thrombolytic therapy in community hospitals (n=99), group B - thrombolytic therapy during transportation to angioplasty (n=100), group C - immediate transportation for primary angioplasty without pre-treatment with thrombolysis (n=101). RESULTS: No complications occurred during transportation in group C. Two ventricular fibrillations occurred during transportation in group B. Median admission-reperfusion time in transported patients (group B 106 min, group C 96 min) compared favourably with the anticipated >90 min in group A. The combined primary end-point (death/reinfarction/stroke at 30 days) was less frequent in group C (8%) compared to groups B (15%) and A (23%, P<0. 02). The incidence of reinfarction was markedly reduced by transport to primary angioplasty (1% in group C vs 7% in group B vs 10% in group A, P<0.03). CONCLUSIONS: Transferring patients from community hospitals to a tertiary angioplasty centre in the acute phase of myocardial infarction is feasible and safe. This strategy is associated with a significant reduction in the incidence of reinfarction and the combined clinical end-point of death/reinfarction/stroke at 30 days when compared to standard thrombolytic therapy at the community hospital.     

Cost effectiveness of thrombolytic treatment for myocardial infarction: comparison of anistreplase, alteplase and streptokinase in 270 patients treated within 4 hours

Two hundred and seventy patients, under 71 years of age andsuffering from a less than 4 h infarction diagnosed accordingto clinical and electrocardiographic criteria, were included.two 90-patient groups were randomized and then treated witheither anistreplase (30 mg iv over 5 min) or alteplase (10 mgbolus injection + 5000 IU heparin bolus injection, followedby 90 mg alteplase over 3 h), and compared with a consecutivecontrol series of 90 patients treated with streptokinase (1.5million U over 1 h). Intravenous heparin and aspirin (250 mgday^–1) were then prescribed routinely. The three groupswere comparable as regards age (55.2±10 years), male/femaleratio (10.4 the site of the infarction (42% anterior, 55% inferior)and initial clinical seriousness (Killip I=90%, II=8%, III=2%).The patients were thombolysed in 17 community hospitals, andthen referred to a university hospital with catheterizationfacilities. An efficacy score was determined, based on fourparameters: two obtained from coronary angiography and leftventriculography performed on day 6±2 (N = 252) (asynergicscore and patency of the infarct-related artery), one from Tl-tomographyperformed at rest (infarct size) and one from radionuclide angiography(global left ventricular ejection fraction) performed betweenday 15 and day 21 (N = 242). The score (range: 0–24 perpatient) was 17.8±6.4 for alteplase, 17.7±6.0for anistreplase and 18.1±6.0 for streptokinase respectively(NS). The real cost of the hospital phase, for each patient,was determined by adding up the cost of thrombolytic treatment(ranging from 1.7% of the total hospital cost for streptokinaseto 16% for alteplase), other treatment and biological examinations(10% of the total cost), coronary angiography, followed in 35%of patients by angioplasty (21% of the overall cost) and hospitalization(ranging from 49% of the total cost for alteplase and anistreplaseto 56% for streptokinase [NS] for an average 17-day hospitalization.Thus, the total cost of the hospital phase was 6460 ECU foralteplase, 6570 ECU for anistreplase and 6050 ECU for streptokinase(NS). The cost/efficacy ratio was 548 ECU for alteplase, 570ECU for anistreplase and 405 ECU for streptokinase. Secondarymortality and re-infarction rates were very low (1.2% and 1.5%respectively) after 1 year following the treatment. However,ischaemia recurred in 23% of patients, requiring revascularizationoperations in 9% of them. Sixty-nine per cent of patients withprofessional occupations were able to resume these activities. This study showed no difference in efficacy between the threethrombolytic agents for the three left ventricular parameters(left ventricular ejection fraction, asynergic score, necroticmass) and for the patency of the infarct-related artery, andalso demonstrated that the cost of the thrombolytic agent hadrelatively little effect on the total cost of myocardial infarction.There could be a potential saving by shortening hospitalization,which accounted for half the cost of thrombolysed myocardialinfarction.     

Reperfusion arrhythmia: myth or reality?

Early reports of "reperfusion arrhythmia" after experimental temporary coronary occlusion raised concern that these arrhythmias, particularly ventricular fibrillation and ventricular tachycardia, might occur in association with reperfusion of an occluded coronary vessel during thrombolysis. Such an occurrence could increase the risk of transfer of such patients. To provide a more definitive answer to this question, we reviewed hospital and transfer records for all patients with acute myocardial infarction transferred by our critical care transfer service between January 1, 1985, and November 30, 1987, noting the occurrence of five types of arrhythmia: ventricular fibrillation, ventricular tachycardia, premature ventricular contractions, bradycardia, and atrioventricular block, both before and during transfer. Five hundred patients with acute myocardial infarction less than 48 hours old were transferred during this period. Two hundred twenty-five patients received thrombolytic therapy; 270 did not (five unknown). The type of acute myocardial infarction was known for 471 patients: 192 were anterior, 203 were inferior, and 76 were lateral. There were no deaths during transfer. Overall survival through hospitalization was 91%. The incidence of arrhythmia was 36% before transport and 12% during transport. There was no difference in arrhythmias overall, or with respect to any of the five arrhythmias specified, between patients who received thrombolytic therapy before and during transport and those who did not. Reperfusion arrhythmia does not appear to be a clinically significant entity during the transport of patients who are receiving IV thrombolytic therapy.     

静脉溶栓后选择性PCI对急性心肌梗死患者远期预后的影响

目的探讨静脉溶栓后选择性经皮冠状动脉介入治疗(PCI)对急性心肌梗死(AMI)患者远期预后的影响.方法AMI患者114例,60例仅接受静脉溶栓者为药物组,54例静脉溶栓后平均(9.1±2.4)d行PCI者为手术组,分别于溶栓后及PCI后3、6、12个月随访主要心脏不良事件(MACE)发生情况.随访复查超声心动图,计算左室的整体室壁运动指数和左室射血分数.结果两组住院期间无死亡及心绞痛复发,手术组血管造影和操作成功率均为100%,无操作相关心肌梗死、急诊冠脉搭桥术(CABG).随访期间死亡率、因不稳定型心绞痛或心绞痛复发再次入院者手术组均显著少于药物组(P＜0.05),手术组总的临床终点事件发生率明显低于药物组(P＜0.01).结论 AMI患者静脉溶栓后选择性PCI能改善其远期预后.     

A systemic non-lytic state and local thrombolytic failure of anistreplase (anisoylated plasminogen streptokinase activator complex, APSAC) in acute myocardial infarction

The relation between coronary thrombolysis and coagulation variables after administration of anistreplase (anisoylated plasminogen streptokinase activator complex, APSAC) was studied in patients with an acute myocardial infarction. Fifty eight consecutive patients with acute myocardial infarction were given 30 U of anistreplase intravenously within 4 hours of the onset of symptoms. A fall in the plasma concentration fibrinogen to less than 1.0 g/l 90 minutes after administration of anistreplase was considered to reflect a systemic lytic state. Coronary angiography was performed 48 hours after thrombolytic treatment. The overall patency rate was 74% (43/58). Patency rates were significantly different in patients with a systemic lytic (83% (43/52)) and a systemic non-lytic state (0% (0/6)). The absence of a systemic lytic state after anistreplase administration seemed to be highly predictive of the failure of coronary thrombolysis. Coagulation studies showed evidence of inhibition of anistreplase induced fibrinolytic activity which may explain the failure of thrombolytic treatment in patients with evidence of a systemic non-lytic state.     

A systemic non-lytic state and local thrombolytic failure of anistreplase (anisoylated plasminogen streptokinase activator complex, APSAC) in acute myocardial infarction.

The relation between coronary thrombolysis and coagulation variables after administration of anistreplase (anisoylated plasminogen streptokinase activator complex, APSAC) was studied in patients with an acute myocardial infarction. Fifty eight consecutive patients with acute myocardial infarction were given 30 U of anistreplase intravenously within 4 hours of the onset of symptoms. A fall in the plasma concentration fibrinogen to less than 1.0 g/l 90 minutes after administration of anistreplase was considered to reflect a systemic lytic state. Coronary angiography was performed 48 hours after thrombolytic treatment. The overall patency rate was 74% (43/58). Patency rates were significantly different in patients with a systemic lytic (83% (43/52)) and a systemic non-lytic state (0% (0/6)). The absence of a systemic lytic state after anistreplase administration seemed to be highly predictive of the failure of coronary thrombolysis. Coagulation studies showed evidence of inhibition of anistreplase induced fibrinolytic activity which may explain the failure of thrombolytic treatment in patients with evidence of a systemic non-lytic state.     

The occurrence and prognostic significance of atrial fibrillation/-flutter following acute myocardial infarction. TRACE Study group. TRAndolapril Cardiac Evalution.

AIMS: To investigate the occurrence and prognostic significance of atrial fibrillation/-flutter following acute myocardial infarction. METHODS AND RESULTS: The occurrence and prognostic significance of atrial fibrillation/-flutter were studied in 6676 consecutive patients with acute myocardial infarction screened in 27 centres in Denmark for inclusion into the TRAndolapril Cardiac Evaluation (TRACE) study. Information about occurrence of atrial fibrillation/-flutter during hospitalization was prospectively collected for the following three periods: day 1-2, day 3-4 and from day 5 until discharge. A total of 1395 patients (21%) suffered from atrial fibrillation/-flutter in one or more of the specified periods during hospitalization. Patients with atrial fibrillation/-flutter were significantly older, a significantly greater proportion were women, left ventricular systolic dysfunction was more extensive, thrombolytic therapy was received less frequently, and anterior Q wave myocardial infarction was experienced more frequently than patients without atrial fibrillation/-flutter. History of acute myocardial infarction and/or angina pectoris was similar in patients with and without atrial fibrillation/-flutter, whereas significantly more patients with atrial fibrillation/-flutter had a history of hypertension, congestive heart failure, diabetes mellitus, pulmonary disease and stroke. The unadjusted in-hospital mortality rate was significantly higher in patients with atrial fibrillation/-flutter in one or more of the specified periods during hospitalization (18%) than in patients without atrial fibrillation/-flutter (9%), P<0.001. After adjustment for baseline characteristics, the presence of atrial fibrillation/-flutter was still associated with increased in-hospital mortality; odds ratio=1.5 (95% Cl: 1.2-1.8), P<0.001. In patients surviving hospitalization, the unadjusted 5-year mortality rate was also significantly higher in patients suffering from atrial fibrillation/-flutter (56%) than in patients without atrial fibrillation/-flutter (34%), P<0.001. After adjustment for important prognostic baseline characteristics, the presence of atrial fibrillation/-flutter was still associated with an increased mortality, relative risk=1.3 (95% Cl: 1.2-1.4). Subgroup analysis revealed that sustained atrial fibrillation/-flutter during hospitalization was associated with the highest risk of dying, relative risk=1.4 (95% Cl: 1.2-1.7). CONCLUSION: Atrial fibrillation/-flutter often occurs after acute myocardial infarction and our analysis demonstrated that it was an independent predictor of an increased short and long-term mortality.     

Efficacy and Safety of Thrombolysis with Intravenous Streptokinase Initiated Prior to Ambulance Transport from Community Hospital to Tertiary Health Care Center

We studied the safety and efficacy of thrombolytic therapy for acute myocardial infarction initiated prior to ambulance transport. Two treatment regimens were compared in a prospective design: 40 patients (group A) received intravenous streptokinase 5 ± 10⁵ IU (SK-IV) prior to and during ambulance transport and were compared with 36 patients (group B) in whom the same dosage of streptokinase was given after arrival in our hospital. In all patients immediate coronary angiography was performed, followed by intracoronary streptokinase administration. Infarct size was assessed by cumulative release of α-hydroxybutyrate dehydrogenase. Apart from three episodes of ventricular fibrillation no procedure-related complications occurred during transport. Median time to SK-IV was 70 minutes in group A versus 125 minutes in group B (P < 0.001). At first visualization the infarct-related vessel was patent in 23 patients (58%) in group A and in 6 patients (17%) in group B (P < 0.001). Anterior wall infarction median infarct size in group A was 32% smaller than that in group B (P < 0.05). We conclude that SK-IV started before ambulance transport is safe, accelerates early reperfusion rate, and consequently leads to a further limitation of infarct size in patients with anterior wall infarction. (J Interven Cardiol 1989:2:3)     

Hypokalaemia and ventricular fibrillation in acute myocardial infarction.

Serum potassium concentrations obtained on admission to hospital were inversely related to the incidence of ventricular fibrillation in 289 women and 785 men with acute myocardial infarction, 92 of whom developed ventricular fibrillation. Hypokalaemia (serum potassium concentration less than or equal to 3.5 mmol/l) was found in 122 patients (11.4%). The incidence of ventricular fibrillation was significantly greater in patients with hypokalaemia compared with those classified as normokalaemic (serum potassium concentration greater than or equal to 3.6 mmol/l) (17.2% v 7.4%). The increased risk of ventricular fibrillation in the hypokalaemic group was about the same for women and men. While they were in hospital patients with hypokalaemia developed ventricular fibrillation significantly earlier than did normokalaemic patients (median 0.3 hours v 7 hours). Hypokalaemia was more common in women (17.3%) than in men (9.2%), and 55% of the hypokalaemic patients had been treated with diuretics before admission compared with 22% of the normokalaemic group. Hypokalaemia on admission to hospital predicts an increased likelihood and early occurrence of ventricular fibrillation in patients with acute myocardial infarction.