Atrial fibrillation associated with acute myocardial infarction: a study of 34 cases

New-onset atrial fibrillation is associated with cardiovascular events leading to death in a first time myocardial infarction population of 89,703 patients with long-term follow-up: a nationwide study

Background

New‐onset atrial fibrillation (AF) is reported to increase the risk of death in myocardial infarction (MI) patients. However, previous studies have reported conflicting results and no data exist to explain the underlying cause of higher death rates in these patients.

Methods and Results

All patients with first acute MI between 1997 and 2009 in Denmark, without prior AF, were identified from Danish nationwide administrative registers. The impact of new‐onset AF on all‐cause mortality, cardiovascular death, fatal/nonfatal stroke, fatal/nonfatal re‐infarction and noncardiovascular death, were analyzed by multiple time‐dependent Cox models and additionally in propensity score matched analysis. In 89 703 patients with an average follow‐up of 5.0±3.5 years event rates were higher in patients developing AF (n=10 708) versus those staying in sinus‐rhythm (n=78 992): all‐cause mortality 173.9 versus 69.4 per 1000 person‐years, cardiovascular death 137.2 versus 50.0 per 1000 person‐years, fatal/nonfatal stroke 19.6/19.9 versus 6.2/5.6 per 1000 person‐years, fatal/nonfatal re‐infarction 29.0/60.7 versus 14.2/37.9 per 1000 person‐years. In time‐dependent multiple Cox analyses, new‐onset AF remained predictive of increased all‐cause mortality (HR: 1.9 [95% CI: 1.8 to 2.0]), cardiovascular death (HR: 2.1 [2.0 to 2.2]), fatal/nonfatal stroke (HR: 2.3 [2.1 to 2.6]/HR: 2.5 [2.2 to 2.7]), fatal/nonfatal re‐infarction (HR: 1.7 [1.6 to 1.8]/HR: 1.8 [1.7 to 1.9]), and non‐ cardiovascular death (HR: 1.4 [1.3 to 1.5]) all P<0.001). Propensity‐score matched analyses yielded nearly identical results (all P<0.001).

Conclusions

New‐onset AF after first‐time MI is associated with increased mortality, which is largely explained by more cardiovascular deaths. Focus on the prognostic impact of post‐infarct AF is warranted.

Atrial fibrillation and mortality in patients with acute myocardial infarction: a systematic overview and meta-analysis

Atrial fibrillation (AF) confers an increased risk of mortality in patients hospitalized for acute myocardial infarction (AMI). However, it is unclear whether new-onset and preexisting AF portend a different risk. We extracted data from studies that evaluated in-hospital mortality in patients with AMI and included information on cardiac rhythm. Overall, the risk of mortality was higher in patients with AF than in those in sinus rhythm (OR 2.00, 95 % CI: 1.93-2.08; P < 0.0001). Compared with patients who remained in sinus rhythm, the risk of death was increased in patients with new AF certain (sinus rhythm on admission, new AF during hospitalization, and history of no evidence of prior AF; OR 3.38, 95 % CI: 2.98-3.83; P < 0.0001), new AF uncertain (sinus rhythm on admission, AF during hospitalization, but no clear information about previous history of AF; OR 1.90, 95 % CI:1.83-1.98; P < 0.0001), and permanent AF (AF before and during hospitalization; OR 2.01, 95 % CI:1.70-2.38;P < 0.0001). In a meta-regression analysis, the risk of death was 87 % higher in patients with new AF certain than in those with permanent AF (P = 0.013) or AF uncertain (P = 0.003), and not dissimilar in patients with new AF uncertain and permanent AF (P = 0.706).

Atrial fibrillation after but not before primary angioplasty for ST-segment elevation myocardial infarction of prognostic importance

AIM

In patients with ST-segment elevation myocardial infarction (STEMI), it is uncertain whether atrial fibrillation has prognostic implications. There may be a difference between atrial fibrillation before and after reperfusion therapy.

METHODS AND RESULTS

In patients with STEMI treated with primary percutaneous coronary intervention (PCI), ECGs were analysed before and after primary PCI. Of the 1623 patients with electrocardiographic data before primary PCI, 53 patients (3.3%) had atrial fibrillation. Patients with atrial fibrillation were older, were more often female, and less often had anterior MI location. Of the 1728 patients with electrocardiographic data after primary PCI, 52 patients (3.0%) had atrial fibrillation. Atrial fibrillation was more common in older patients and in those with Killip class >1. Also patients with occlusion of the right coronary artery or TIMI flow 0 before primary PCI more commonly had AF after the procedure. Not successful reperfusion was also associated with a higher incidence of AF after primary PCI. Although both atrial fibrillation before and after primary PCI were associated with increased mortality, multivariable analyses, adjusting for differences in age, gender and Killip class on admission, revealed that atrial fibrillation after PCI (OR 3.69, 95% CI 1.87-7.29) but not before PCI (OR 1.86, 95% CI 0.89-3.90) was independent and statistically significantly associated with long-term mortality.

CONCLUSION

In patients with STEMI, atrial fibrillation after but not before primary PCI has independent prognostic implications. Possibly, atrial fibrillation after the PCI is a symptom of failed reperfusion and a sign of heart failure.

Mortality associated with atrial fibrillation in patients with myocardial infarction: a systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) is a common finding in patients with myocardial infarction (MI). Atrial fibrillation is not generally perceived by clinicians as a critical event during the acute phase of MI; however, its prognostic influence in MI remains controversial. Furthermore, contradictory data exist concerning the risk of death according to AF timing. This article, a systematic review and first meta-analysis, aims to quantify the mortality risk associated with AF in MI patients and its timing.

METHODS AND RESULTS

A comprehensive search of several electronic databases (1970 to 2010; adults, any language) identified MI studies that evaluated mortality related to AF. Evidence was reviewed by 2 blinded reviewers with a formal assessment of the methodological quality of the studies. Adjusted odds ratios were pooled across studies using the random-effects model. The I(2) statistic was used to assess heterogeneity. In the 43 included studies (278 854 subjects), the mortality odds ratio associated with AF was 1.46 (95% confidence interval, 1.35 to 1.58; I(2)=76%; 23 studies). This worse prognosis persisted regardless of the timing of AF; the odds ratio of mortality for new AF with no prior history of AF was 1.37 (95% confidence interval, 1.26 to 1.49), I(2)=28%, 9 studies), and for prior AF was 1.28 (95% confidence interval, 1.16 to 1.40; I(2)=24%; 4 studies). The sensitivity analysis of new AF studies adjusting for confounding factors did not show a decrease in risk of death.

CONCLUSIONS

Atrial fibrillation is associated with increased risk of mortality in MI patients. New AF with no history of AF before MI remained associated with an increased risk of mortality even after adjustment for several important AF risk factors. These subsequent increases in mortality suggest that AF can no longer be considered a nonsevere event during MI.

Effect of reperfusion on P-wave duration and P-wave dispersion in acute myocardial infarction: primary angioplasty versus thrombolytic therapy

BACKGROUND

Atrial fibrillation (AF) is a common arrhythmia occurring in about 10-20% of patients with acute myocardial infarction (AMI). P-wave dispersion (PWd) and P-wave duration (PWD) have been used to evaluate the discontinuous propagation of sinus impulse and the prolongation of atrial conduction time, respectively. This study was conducted to compare the effects of reperfusion either by thrombolytic therapy or primary angioplasty on P-wave duration and dispersion in patients with acute anterior wall myocardial infarction.

METHODS

We have evaluated 72 consecutive patients retrospectively (24 women, 48 men; aged 58 +/- 12 years) experiencing acute anterior wall myocardial infarction (AMI) for the first time. Patients were grouped according to the reperfusion therapy received (primary angioplasty (PTCA) versus thrombolytic therapy). Left atrial diameter and left ventricular ejection fraction (LVEF) were determined by echocardiography in all patients. Electrocardiography was recorded from all patients on admission and every day during hospitalization. Maximum (P max) and minimum (P min) P-wave durations and P-wave dispersions were calculated before and after the treatment.

RESULTS

There were not any significant differences between the groups regarding age, gender, left ventricular ejection fraction, left atrial diameter and volume, cardiovascular risk factors, and duration from symptom onset to treatment. P-wave dispersions and P-wave durations were significantly decreased after PTCA [Mean P max was 113 +/- 11 ms before and 95 +/- 17 ms after the treatment (P = 0.007)]. Mean PWd was 46 +/- 12 ms before and 29 +/- 10 ms after the treatment (P = 0.001). Also, P max and PWd were significantly lower in PTCA group (for P max 97 +/- 22 ms vs 114 +/- 16 ms and for PWd 31 +/- 13 ms vs 55 +/- 5 ms, respectively).

CONCLUSIONS

Primary angioplasty reduces the incidence of AF by decreasing P max and P-wave dispersion.

Incidence and prognostic significance of atrial fibrillation in acute myocardial infarction: the GISSI-3 data

BACKGROUND

Atrial fibrillation is the most common supraventricular arrhythmia in patients with acute myocardial infarction. Recent advances in pharmacological treatment of myocardial infarction may have changed the impact of this arrhythmia.

OBJECTIVE

To assess the incidence and prognosis of atrial fibrillation complicating myocardial infarction in a large population of patients receiving optimal treatment, including angiotensin converting enzyme (ACE) inhibitors.

METHODS

Data were derived from the GISSI-3 trial, which included 17 944 patients within the first 24 hours after acute myocardial infarction. Atrial fibrillation was recorded during the hospital stay, and follow up visits were planned at six weeks and six months. Survival of the patients at four years was assessed through census offices.

RESULTS

The incidence of in-hospital atrial fibrillation or flutter was 7.8%. Atrial fibrillation was associated with indicators of a worse prognosis (age > 70 years, female sex, higher Killip class, previous myocardial infarction, treated hypertension, high systolic blood pressure at entry, insulin dependent diabetes, signs or symptoms of heart failure) and with some adverse clinical events (reinfarction, sustained ventricular tachycardia, ventricular fibrillation). After adjustment for other prognostic factors, atrial fibrillation remained an independent predictor of increased in-hospital mortality: 12.6% v 5%, adjusted relative risk (RR) 1.98, 95% confidence interval (CI) 1.67 to 2.34. Data on long term mortality (four years after acute myocardial infarction) confirmed the persistent negative influence of atrial fibrillation (RR 1.78, 95% CI 1.60 to 1.99).

CONCLUSIONS

Atrial fibrillation is an indicator of worse prognosis after acute myocardial infarction, both in the short term and in the long term, even in an unselected population.

Breath-hold three-dimensional contrast-enhanced coronary MR angiography: motion-matched k-space sampling for reducing cardiac motion effects

A view order that matches k-space sampling to cardiac motion within the acquisition window was developed for breath-hold three-dimensional contrast material-enhanced coronary magnetic resonance angiography. In vivo experiments in seven volunteers demonstrated that blurring was substantially reduced with this motion-matched view order as compared with the standard centric view order. Coronary arteries were well delineated.

Impact of atrial fibrillation on the in-hospital and long-term survival of patients with acute myocardial infarction: a community-wide perspective

As part of an ongoing community-wide study examining changes over time in the incidence and survival rates of 4108 patients hospitalized with validated acute myocardial infarction (MI) in 16 hospitals in the Worcester, Massachusetts, metropolitan area during calendar years 1975, 1978, 1981, 1984, and 1986, we examined changes over time in the proportion of patients with acute MI developing atrial fibrillation (AF) and the impact of AF on in-hospital and long-term survival for up to a 10-year follow-up period. The overall percentage of patients with AF complicating acute MI was 16.0%; this proportion increased over time from 13.3% in 1975 to 14.8% in 1978, 14.9% in 1981, 20.3% in 1984, and to 17.7% in 1986. Patients with AF experienced consistently higher in-hospital case fatality rates than MI patients without AF overall (27.6% versus 16.6%), as well as during each of the 5 years under study. The independent effect of AF on in-hospital survival was not upheld, however, when a variety of potentially confounding prognostic factors were controlled for in a multivariate analysis resulting in an adjusted odds ratio (OR) of 1.18 (95% confidence interval 0.90, 1.52). Among discharged hospital patients, while the crude long-term survival rate for patients with AF was poorer than that of patients without AF for the combined as well as for individual study periods, similar to the in-hospital findings the independent effect of AF on long-term prognosis was not upheld after use of a multivariate analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Supraventricular arrhythmias in the late hospital phase of acute Q-wave myocardial infarction. Supraventricular arrhythmia in myocardial infarction

To assess the correlates of supraventricular arrhythmia (SA) in the late hospital phase of acute Q-wave myocardial infarction (MI), continuous 24-h ambulatory electrocardiographic monitoring, gated cardiac pool scan, modified exercise test, and chest x-ray were reviewed in 102 patients. Supraventricular tachyarrhythmias were seen in 11 patients, atrial premature beats in 42 patients; 49 patients did not have SA. Multiple discriminant analysis was used to determine the important variables contributing to the occurrence of SA. Variable included age, sex, history of previous MI, hypertension, location of MI, moist rales at time of admission, cardiothoracic ratio, ejection fraction, wall motion abnormality, exercise test result, duration of exercise and use of digitalis. Moist rales, digitalis, age and cardiothoracic ratio were the predictors of SA. Aging, hemodynamic change imposed on the left ventricle, and arrhythmic effects of digitalis are the major factors associated with SA in the late hospital phase of acute MI.

Early atrial fibrillation during evolving myocardial infarction: a consequence of impaired left atrial perfusion

Seven of 214 patients (3%) with acute myocardial infarction (120 inferior and 94 anterior) developed atrial fibrillation within 3 hr of the onset of chest pain. All seven patients had an inferior infarction and in all seven the left circumflex artery was occluded proximal to the origin of its left atrial circumflex branch. In five patients this occlusion was acute and was the cause of inferior infarction and in the remaining two patients the occlusion was old and the inferior infarction was due to an acute occlusion of the right coronary artery that also supplied extensive collaterals to the previously occluded left circumflex artery. All seven patients also had impaired perfusion to the atrioventricular nodal artery, as evidenced by total occlusion proximal to its origin or by stenosis proximal to its origin associated with second- or third-degree atrioventricular block. In contrast, early atrial fibrillation did not occur in any of the 18 patients with inferior myocardial infarction due to acute occlusion of the distal left circumflex artery or in any of the five patients with inferior infarction due to acute occlusion of the proximal left circumflex artery if perfusion to the atrioventricular nodal artery was not impaired. Early atrial fibrillation did not occur in any of the 90 patients with inferior infarction due to acute occlusion of the right coronary artery, including 12 patients with occlusion proximal to the sinus nodal artery, but without coexistent occlusion of the left circumflex artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial fibrillation in acute myocardial infarction

To elucidate the genesis and effect of atrial fibrillation (AF), 102 patients with acute myocardial infarction were studied. Eighteen patients had AF during the first 72 hours in the coronary care unit. The hospital mortality rate was 23%. Discriminant analysis was used to determine the important variables contributing to the genesis of AF and hospital mortality based on the following variables: cardiac output, pulmonary capillary wedge pressure, right atrial pressure, systolic blood pressure (at admission and before the onset of AF or most abnormal value), age, location of infarction, sex and pericarditis. Pulmonary capillary wedge pressure, right atrial pressure and age were the important factors contributing to AF, whereas pulmonary capillary wedge pressure and age were important for hospital mortality. Therefore, the hemodynamic change imposed on the left atrium and aging are the major factors related to the occurrence of AF and hospital mortality.

Coronary heart disease mortality/morbidity and risk in blacks. I: Clinical manifestations and diagnostic criteria: the experience with the Beta Blocker Heart Attack Trial

A comparison was made of the clinical manifestations and diagnostic criteria of coronary artery disease in black and nonblack patients in the cohort of participants in the Beta Blocker Heart Attack Trial (BHAT). Although diagnostic criteria were uniform for all potential participants in the trial, examination of the baseline data indicates that black patients had a higher proportion of cardiomegaly and ECGs with left ventricular hypertrophy with ST-T wave changes and a lower percentage of transmural myocardial infarction in comparison to nonblack patients. Baseline data also show that blacks, in comparison to nonblacks, had a higher percentage of variables shown to be characteristic of the high-risk group, including current smoking status, rapid heart rate, angina, high blood pressure, elevated cholesterol, diuretic use, and vasodilator use. The Cox regression analysis confirmed the positive association of these risk descriptors with outcome for the overall study. Walker-Duncan multivariate regression analysis ascribed significance of these risk descriptors to nonblacks only. Blacks (n = 333) had placebo and treatment mortality rates of 15.9 and 11.7, compared to 9.8 and 7.2, respectively, for the overall study (n = 3837). Thus the reduction in mortality among blacks who received propranolol after a recent myocardial infarction was shown to be comparable to that of the other high-risk groups in the BHAT.

Atrial fibrillation--a marker for abnormal left ventricular function in coronary heart disease

Retrospective study of 1176 patients with known coronary heart disease by cardiac catheterisation disclosed 10 patients (0.8%) with atrial fibrillation. Comparison with 25 randomly selected patients with coronary heart disease with sinus rhythm showed that atrial fibrillation correlated significantly with impaired haemodynamic function, mitral regurgitation, and abnormalities of left ventricular contraction. Atrial fibrillation is, therefore, a useful marker of extensive myocardial dysfunction.

The prognostic value of the P wave morphology in the discharge ECG in a 5-year follow-up study after myocardial infarction

The discharge ECG's of 641 patients with acute myocardial infarction (AMI) (WHO categories "definite" and "possible" AMI) were studied to assess the prognostic value of P wave morphology as an index of left ventricular dysfunction. Of 69 patients with abnormal P terminal force (PTF), i.e., --0.03 mm.sec. or more negative, 53.6 per cent died within the next 5 years of ischemic heart disease, compared with 20.4 per cent of 558 patients with normal PTF. The odds ratio (age-corrected risk to die, Mantel-Haenszel test) was 4.1 (95 per cent confidence limits 2.4 to 7.0). The mortality curve of patients with normal PTF was linear whereas there was an abrupt rise in mortality rate during the first six months if PTF was abnormal. Of a group of 15 patients with the frontal axis of the terminal P wave --30 degrees or more negative, 8 died (Odds ratio 4.7; 1.3 to 17.1). Ten patients had atrial fibrillation, and five of them died (Odds ratio 2.; 0.5 to 12.9). In 14 cases the duration of the P wave in Lead II was 0.12 sec. but it showed no relationship to mortality (p less than 0.10). The significance of the P wave morphology on the discharge ECG to long-term survival after MI has been demonstrated. These simple ECG variables, related to left ventricular failure, can easily be put to clinical use to differentiate MI patients who are in greater risk of dying during the chronic phase.

Effects of atrial fibrillation on prognosis of acute myocardial infarction

Nine hundred and sixty-nine coronary care patients with acute myocardial infarction were followed for one year. Atrial fibrillation was documented in 107 patients. Compared with patients without atrial fibrillation, those with this arrhythmia were older, had clinically more severe infarction, and had a higher frequency of ventricular fibrillation or tachycardia, and right bundle-branch block. They had similar past histories of ischaemic heart disease and coronary risk factors. Patients with atrial fibrillation had a higher total mortality at 3 months and 12 months. The presence of atrial fibrillation was not associated with any significant increase in mortality within any decade of age or within any subgroup of clinical severity of infarction. The frequency of atrial fibrillation was similar in anterior and inferior infarction. Multiple episodes of atrial fibrillation occurred in 52 patients and episodes usually lasted for over 1 hour. In 50% of patients with single episode of atrial fibrillation the initial ventricular rate was greater than 120 beats per minute.

Atrial fibrillation developing in the acute phase of myocardial infarction. Prognostic implications

Atrial fibrillation was observed in 39 (11 percent) of 350 instances of acute myocardial infarction. The mortality among these patients was 41 percent (16/39). Atrial fibrillation was more common in patients with undetermined infarctions and in older people. As opposed to death rates close to 50 percent among patients with anterior, combined, and undetermined infarctions, the presence of atrial fibrillation did not affect the mortality among patients with inferior infarctions (10 percent, 1/10). Ventricular rates higher than 120 beats per minute and duration of the arrhythmia longer than six hours were not associated with increased mortality. Hemodynamic failure was present in almost all of the cases and preceded the arrhythmia in most of them. It is concluded that different mechanisms are responsible for the production of atrial fibrillation in the setting of acute myocardial infarction, and the prognosis of the patient is related to the mechanism of production and not to the arrhythmia itself.