Relation between myocardial infarct location and stroke

Associations between the size and location of myocardial infarction and cerebral infarction

BACKGROUND

Myocardial infarction (MI) is a known cause of cerebral infarction. We assessed whether the size and location of MI is associated with the risk of cerebral infarction.

METHODS AND RESULTS

We performed a cross-sectional study of adults who underwent both brain MRI and delayed-enhancement cardiac MRI (DE-CMR) within 365 days of each other at Weill Cornell Medicine between 2014 and 2017 and had evidence of MI on DE-CMR. We used multiple logistic regression to evaluate associations between MI size and any cerebral infarction, apical MI location and any cerebral infarction, and MI size/location and cortical versus subcortical cerebral infarction. Models were adjusted for demographics, and the total number of vascular risk factors. Among 234 patients who underwent both DE-CMR and brain MRI within 365 days, 76 had evidence for MI on DE-CMR. Among these 76 patients, 51 (67.1%) had evidence of cerebral infarction. The size of MI (global MI burden) was not associated with any cerebral infarction (OR per 5% increase in MI size, 1.12; 95% CI, 0.85-1.47), but was associated with cortical cerebral infarction (OR per 5% increase in MI size, 1.30; 95% CI, 1.00.-1.68). Similarly, apical MI location was not associated with any cerebral infarction (OR 2.63, 95% CI, 0.78-8.87), but was associated with cortical cerebral infarction (OR, 3.67; 95% CI, 1.19-11.33).

CONCLUSION

Among patients with MI on cardiac MRI, both size and apical location of MI were associated with cortical cerebral infarction. Our results may help stratify cardioembolic risk and inform antithrombotic treatment algorithms among patients with MI.

Twenty-Five-Year (1986-2011) Trends in the Incidence and Death Rates of Stroke Complicating Acute Myocardial Infarction

BACKGROUND

The occurrence of a stroke after an acute myocardial infarction is associated with increased morbidity and mortality rates. However, limited data are available, particularly from a population-based perspective, about recent trends in the incidence and mortality rates associated with stroke complicating an acute myocardial infarction. The purpose of this study was to examine 25-year trends (1986-2011) in the incidence and in-hospital mortality rates of initial episodes of stroke complicating acute myocardial infarction.

METHODS

The study population consisted of 11,436 adults hospitalized with acute myocardial infarction at all 11 medical centers in central Massachusetts on a biennial basis between 1986 and 2011.

RESULTS

In this study cohort, 159 patients (1.4%) experienced an acute first-ever stroke during hospitalization for acute myocardial infarction. The proportion of patients with acute myocardial infarction who developed a stroke increased through the 1990s but decreased slightly thereafter. Compared with patients who did not experience a stroke, those who experienced a stroke were significantly older, were more likely to be female, had a previous acute myocardial infarction, had a significant burden of comorbidities, and were more likely to have died (32.1% vs 10.8%) during their index hospitalization. Patients who developed a first stroke in the most recent study years (2003-2011) were more likely to have died during hospitalization than those hospitalized during earlier study years.

CONCLUSIONS

Although the incidence rates of acute stroke complicating acute myocardial infarction remained relatively stable during the years under study, the in-hospital mortality rates of those experiencing a stroke have not decreased.

Frequency and Predictors of Stroke After Acute Myocardial Infarction

Background and Purpose—

Stroke is a serious complication after acute myocardial infarction (AMI) and is closely associated with decreased survival. This study aimed to investigate the frequency, characteristics, and factors associated with in-hospital and postdischarge stroke in patients with AMI.

Methods—

Eight thousand four hundred eighty-five consecutive patients admitted to a cardiology intensive care unit for AMI, between January 2001 and July 2010. Stroke/transient ischemic attack were collected during 1-year follow-up.

Results—

One hundred twenty-three in-hospital strokes were recorded: 65 (52.8%) occurred on the first day after admission for AMI, and 108 (87%) within the first 5 days. One hundred six patients (86.2%-incidence rate 1.25%) experienced in-hospital ischemic stroke, and 14 patients (11.4%-incidence rate 0.16%) were diagnosed with an in-hospital hemorrhagic stroke. In-hospital ischemic stroke subtypes according to the Trial of Org 10 172 in Acute Stroke Treatment (TOAST) classification showed that only 2 types of stroke were identified more frequently. As expected, the leading subtype of in-hospital ischemic stroke was cardioembolic stroke (n=64, 60%), the second was stroke of undetermined pathogenesis (n=38, 36%). After multivariable backward regression analysis, female sex, previous transient ischemic attack (TIA)/stroke, new-onset atrial fibrillation, left ventricular ejection fraction (odds ratio per point of left ventricular ejection fraction), and C-reactive protein were independently associated with in-hospital ischemic stroke. When antiplatelet and anticoagulation therapy within the first 48 hours was introduced into the multivariable model, we found that implementing these treatments (≥1) was an independent protective factor of in-hospital stroke. In-hospital hemorrhagic stroke was dramatically increased (5-fold) when thrombolysis was prescribed as the reperfusion treatment. However, the different parenteral anticoagulants were not predictors of risk in univariable analysis. Finally, only 45 postdischarge strokes were recorded. Postdischarge stroke subtypes showed a more heterogeneous distribution of mechanisms. The annual rate of stroke post-AMI remained stable throughout the 10-year study period.

Conclusions—

The present study describes specific predictors of in-hospital and postdischarge stroke in patients with AMI. It showed a marked increase in the risk of death, both during hospitalization and in the year after AMI. After hospital discharge, stroke remains a rare event and is mostly associated with high cardiovascular risk.

Interactions between cardiovascular and cerebrovascular disease

OPININION STATEMENT: All patients with ischemic stroke should undergo a comprehensive assessment of cardiovascular risk. Patients with carotid artery disease, symptoms of cerebral ischemia and high cardiovascular risk profiles should be considered for noninvasive testing for coronary artery disease (CAD). Routine testing for CAD before carotid endarterctomy is not recommended. Patients with coexisting coronary and carotid artery disease should be more aggressively treated for reducing their "very high" risk of cardiovascular events. In patients candidates to carotid revascularization, a preoperative coronary angiography and coronary revascularization are not recommended. Warfarin is recommended in all patients with moderate to high risk of stroke. Novel oral anticoagulants represent an attractive alternative to warfarin. However, their place in therapy in clinical practice is not yet established. Percutaneous closure of the left atrial appendage for stroke prophylaxis may be considered in selected patients with atrial fibrillation and contraindications for oral anticoagulant therapy. Warfarin is not indicated in patients with heart failure who are in sinus rhythm. Percutaneous closure of patent foramen does not seem to be superior to medical therapy for the prevention of recurrences in patients with cryptogenic stroke.

Anticoagulation after anterior myocardial infarction and the risk of stroke

Background

Survivors of anterior MI are at increased risk for stroke with predilection to form ventricular thrombus. Commonly patients are discharged on dual antiplatelet therapy. Given the frequency of early coronary reperfusion and risk of bleeding, it remains uncertain whether anticoagulation offers additional utility. We examined the effectiveness of anticoagulation therapy for the prevention of stroke after anterior MI.

Methods and Findings

We performed a population-based cohort analysis of 10,383 patients who survived hospitalization for an acute MI in Ontario, Canada from April 1, 1999 to March 31, 2001. The primary outcome was four-year ischemic stroke rates compared between anterior and non-anterior MI patients. Risk factors for stroke were assessed by multivariate Cox proportional-hazards analysis. Warfarin use was determined at discharge and followed for 90 days among a subset of patients aged 66 and older (n = 1483). Among the 10,383 patients studied, 2,942 patients survived hospitalization for an anterior MI and 20% were discharged on anticoagulation therapy. Within 4 years, 169 patients (5.7%) were admitted with an ischemic stroke, half of which occurred within 1-year post-MI. There was no significant difference in stroke rate between anterior and non-anterior MI patients. The use of warfarin up to 90 days was not associated with stroke protection after anterior MI (hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.37–1.26). The use of angiotensin-converting-enzyme inhibitors (HR, 0.65; 95% CI, 0.44–0.95) and beta-blockers (HR, 0.60; 95% CI, 0.41–0.87) were associated with a significant decrease in stroke risk. There was no significant difference in bleeding-related hospitalizations in patients who used warfarin for up to 90 days post-MI.

Conclusion

Many practitioners still consider a large anterior-wall MI as high risk for potential LV thrombus formation and stroke. Among a cohort of elderly patients who survived an anterior MI there was no benefit from the use of warfarin up to 90 days post-MI to prevent ischemic stroke. Our data suggests that routine anticoagulation of patients with anterior-wall MI may not be indicated. Prospective randomized trials are needed to determine the optimal antithrombin strategy for preventing this common and serious adverse outcome.

Selective risk factors profiles and outcomes among patients with stroke and history of prior myocardial infarction. The European Community Stroke Project

BACKGROUND AND OBJECTIVE

Previous myocardial infarction (MI) has been linked with poorer stroke outcome. Whether this depends on a greater stroke severity is still uncertain. The aim of the study was to assess the effect of previous MI on characteristics and outcome of stroke in a large hospital cohort of patients.

METHODS

In a European Union Concerted Action, patients hospitalized for first-in-a-lifetime stroke were assessed for demographics, risk factors, clinical presentation, and 3-month survival and handicap.

RESULTS

Out of 4190 study patients, 460 (11%) reported a history of MI. Compared with patients without previous MI, those with MI were significantly older, more often males, smokers, alcohol consumers, and with a more severe pre-stroke level of handicap. They had more frequently atrial fibrillation and a history of transient ischemic attack. The acute neurological state and the 28-day mortality did not differ between the two groups. At 3 months, death or severe handicap were more frequent in the MI group (28.3% vs. 21.7%, P=0.001; 74.8% vs. 65.8%, P=0.008). Controlling by logistic regression analysis for age, sex, vascular risk factors, comorbidities, prior to stroke therapy, pre-stroke level of handicap, and clinical acute phase variables, prior MI remained an independent predictor of 3-month death (OR 1.30; 95% CI, 1.02-1.66) and 3-month handicap (OR 1.46; 95% CI, 1.01-2.11).

CONCLUSIONS

Previous MI has no impact on clinical severity of acute stroke, but significantly affects 3-month outcome in terms of handicap and mortality.

Incidence and Prevention of Ischemic Stroke following Myocardial Infarction: Review of Current Literature

Myocardial infarction is the leading cause of death today. With the fast progress in pharmacotherapy and revascularization technology, outcomes following a myocardial infarction have become very favorable. While most of the complications from a myocardial infarction can be adequately managed, thus leading to reduced mortality, stroke following a myocardial infarction remains a challenge even today, and can lead to potentially devastating complications. We discuss the incidence, pathophysiology, and management options of non-hemorrhagic stroke following a myocardial infarction.

Early Coronary Revascularization Diminishes the Risk of Ischemic Stroke With Acute Myocardial Infarction

Background and Purpose— Ischemic stroke is an uncommon but devastating complication of myocardial infarction (MI). It is possible that delay in the acute revascularization of these patients influences the risk of peri-MI ischemic stroke independent of size of infarction or residual ventricular function. The influence of the timing and type of revascularization on risk of ischemic stroke in the patient with MI has not previously been assessed.

Methods— We used the National Registry of Myocardial Infarction 3 and 4 databases to identify 45 997 subjects who received thrombolytic therapy and 47 876 patients who were treated with primary percutaneous transluminal coronary angioplasty for MI. In-hospital ischemic stroke occurred in 248 (0.54%) and 150 (0.31%) patients in the two groups, respectively. Patients were stratified based on time from presentation to initial therapy.

Results— A statistically significant linear relationship between time to revascularization therapy and risk of in-hospital ischemic stroke was seen on univariate analysis. A multivariate model incorporating 26 other variables showed thrombolytic therapy within 15 minutes was associated with a lower risk of ischemic stroke (odds ratio, 0.58; 95% CI, 0.36–0.94). Primary angioplasty within 90 minutes of arrival was associated with a nonsignificant trend toward lower stroke risk (odds ratio, 0.68; 95% CI, 0.41–1.12). Interestingly, his benefit of early reperfusion therapy did not appear to be related to improvements in left ventricular function.

Conclusion— Risk of in-hospital ischemic stroke with MI is closely tied to the time to revascularization with both thrombolytic and percutaneous transluminal coronary angioplasty therapies. Early revascularization is independently predictive of a lower risk of ischemic stroke, but the mechanism of this does not appear to be related to improved cardiac function. The records of 45 997 subjects who received thrombolytic therapy and 47 876 patients who were treated with primary percutaneous transluminal coronary angioplasty for myocardial infarction were analyzed to determine the relationship between time to revascularization and the occurrence of ischemic stroke. A statistically significant linear relationship between time to revascularization therapy and risk of in-hospital ischemic stroke was seen on univariate analysis. A multivariate model incorporating 26 other variables showed thrombolytic therapy within 15 minutes of presentation was associated with a lower risk of ischemic stroke, and angioplasty within 90 minutes was similarly associated with a nonsignificant trend toward lower stroke risk.

Trends (1986 to 1999) in the incidence and outcomes of in-hospital stroke complicating acute myocardial infarction (The Worcester Heart Attack Study)

Although stroke is an infrequent hospital complication of acute myocardial infarction (AMI), limited contemporary data are available about the incidence and death rates associated with this serious complication. The objective of this population-based study was to examine temporal trends (1986 to 1999) in the risk of stroke and associated hospital outcomes in patients hospitalized with AMI. This was an observational study of 6,325 metropolitan Worcester, Massachusetts, residents hospitalized with validated AMI and without prior stroke at all greater Worcester hospitals during 8 one-year periods between 1986 and 1999. Overall, 1.5% of patients (n = 92) with confirmed AMI developed an acute stroke during their index hospitalization. Decreases, followed by increases, in the risk of acute stroke were observed between 1986 and 1999. The highest risk for stroke was observed in the most recent study year of 1999 (3.0%). Several demographic, medical history, and clinical characteristics were associated with an increased risk of stroke overall and separately in younger and older patients hospitalized with AMI. Patients developing an acute stroke had a significantly increased risk of dying during hospitalization even after controlling for other factors of prognostic importance (adjusted odds ratio 4.26, 95% confidence interval 2.49 to 7.31). The results of this community-wide study provide insights into recent trends in the development of acute stroke after AMI and into the profile of high-risk patients.

Risk and predictors of stroke after myocardial infarction among the elderly: results from the Cooperative Cardiovascular Project

BACKGROUND

Stroke is an important outcome after acute myocardial infarction. Studies that have examined this relationship have largely excluded older patients, even though half of stroke admissions occur among patients 75 years of age and older.

METHODS AND RESULTS

Among 111 023 medicare patients discharged with a principal diagnosis of acute myocardial infarction during an 8-month period in 1994 to 1995, we identified hospital admissions for ischemic stroke within 6 months of discharge. The rate of admission was 2.5% within 6 months. Independent predictors of ischemic stroke were age greater-than-or-equal 75 years, black race, no aspirin at discharge, frailty, prior stroke, atrial fibrillation, diabetes, hypertension, and history of peripheral vascular disease. To identify individuals at increased risk for stroke, a risk stratification score was constructed from identified factors. The 6-month stroke admission rate for patients with a score of 4 or higher (approximately 20% of the total sample) was approximately 4%.

CONCLUSIONS

The risk of stroke after myocardial infarction is substantial, with about 1 in 40 patients suffering an ischemic stroke within 6 months of discharge. Simple clinical factors can predict the risk of stroke and, based on these factors, we identified 20% of older patients who have a 1 in 25 chance of being hospitalized for a stroke within 6 months of discharge.

Mechanisms of cardioembolic stroke

Cardiac embolism is often involved as a mechanism for embolic stroke, and may be implicated in many strokes that have traditionally been considered of unknown origin (cryptogenic strokes). In recent years, significant advancements have been made in understanding and reducing the risk of stroke from long-known cardioembolic sources (atrial fibrillation, intracardiac thrombus or tumor, infective endocarditis). Also, improved cardiac imaging, especially transesophageal echocardiography, has allowed the identification of newer embolic sources of stroke (aortic atheromas, patent foramen ovale, atrial septal aneurysm). This article reviews the current understanding of cardiac embolism as a mechanism for stroke, and the preventive options that are currently adopted to decrease the stroke risk.

Cerebral microembolism in acute myocardial infarction

BACKGROUND AND PURPOSE

This study was undertaken to determine the frequency of cerebral microemboli (high-intensity transient signals; HITS) detected by transcranial Doppler (TCD) in patients with acute myocardial infarction (AMI) and to relate them to the various putative risk factors and clinical embolic events.

METHODS

We investigated 112 consecutive patients within 72 hours of admission to an acute coronary care unit using TCD to monitor for cerebral microemboli. Twelve patients were excluded because of failure of ultrasound insonation. All patients had 2-dimensional echocardiograms within the study period.

RESULTS

HITS were detected in 17% of patients, with significantly higher frequency in patients with reduced (<65%) left ventricular (LV) ejection fraction (P=0. 019), akinetic LV segments (P=0.002), and LV thrombus (P=0.015). A marginally significant (P=0.059) increase of HITS was found in patients with anterior AMI. Stroke was significantly more frequent in patients with cerebral microemboli (P=0.01).

CONCLUSIONS

HITS were detected in 17% of patients in spite of adequate antithrombotic therapy and were increased in patients with reduced LV function, akinetic myocardial segments, and LV thrombus. They were present in all 3 patients with stroke and may represent a predictor of clinical embolic events.

Ischemic stroke. Impact of a recent myocardial infarction

BACKGROUND AND PURPOSE

The risk of ischemic stroke is increased after a myocardial infarction. We quantified the stroke risk and evaluated ischemic stroke characteristics after an acute myocardial infarction.

METHODS

A case-control study including patients with first-ever stroke was undertaken. Cases (n=103) were recorded prospectively in the population-based Northern Sweden World Health Organization Multinational Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA) study. Two controls per case with a stroke but without a recent myocardial infarction were matched for age, sex, and year of stroke onset.

RESULTS

The sudden onset of neurological symptoms (76.7% versus 54.9%, P<0.001), impairment of consciousness (35.0% versus 18.4%, P<0.01), and a progression in neurological deficits (19.4% versus 8.7%, P<0.01) were more common in cases, while the onset of stroke during sleep was rarer in cases (6.8% versus 21.4%, P<0.01). In cases and controls, the clinical subclasses of stroke were as follows: total anterior circulation infarcts, 51.5% versus 37.9% (P<0.05); partial anterior circulation infarcts, 28.2% versus 26.7% (P=NS); lacunar infarcts, 4.8% versus 27.2% (P<0.001); and posterior circulation infarcts, 15.5% versus 8.2% (P=0.051). During the first 28 days after myocardial infarction, the daily rate of stroke declined rapidly from approximately 9 to 1 stroke per 10 000 myocardial infarction patients compared with an age-adjusted average daily stroke rate of 0.14 per 10 000 in the MONICA population.

CONCLUSIONS

We conclude that the clinical characteristics of the stroke differ between patients with and without a recent myocardial infarction. The risk of a first-ever ischemic stroke is highest during the first few days after a myocardial infarction, but it then declines rapidly, and the absolute number of stroke events is low.

Ischemic cerebral infarction after rt-PA and heparin therapy for acute myocardial infarction. The TIMI-II pilot and randomized clinical trial combined experience

BACKGROUND AND PURPOSE

Ischemic cerebral infarction (CI) is a serious complication of acute myocardial infarction (MI). Little information exists on CI after thrombolytic therapy for MI.

METHODS

Of 3924 MI patients treated with recombinant tissue plasminogen activator (rt-PA) and heparin, 29 (0.7%) developed CI after treatment. All CI patients had detailed neurological evaluations, and 27 (93%) had CT scans centrally reviewed.

RESULTS

Age range was 40 to 74 years (mean, 60 years); 25 patients (86%) were men, and 22 (76%) were white. The electrocardiographic location of MI was anterior in 22 (76%) and nonanterior in 7 (24%). Five CIs occurred within 6 hours, 4 between 6 to 24 hours, 8 during the remainder of the first week, 10 during the second week, and 2 others distributed over the 4 weeks after study entry. Six of 29 CIs did not involve the cerebral cortex; 9 patients (31%) had multiple CIs. Of 28 CIs thought to be embolic in origin, 17 showed strong evidence for at least one cardiac abnormality (mural clot, wall-motion abnormality, aneurysm, or atrial fibrillation) known to be associated more specifically with embolism than MI. Eight of 27 CIs (30%) with CT scans had hemorrhagic transformation of varying degrees; 5 were symptomatic.

CONCLUSIONS

The time of occurrence and sites of CI after rt-PA and heparin therapy for acute MI are similar to those reported during the prethrombolytic era.

Ischemic stroke after acute myocardial infarction. A population-based study

BACKGROUND AND PURPOSE

Modern treatment may have influenced the risk of stroke after myocardial infarction (MI). The purpose of this study was to examine the incidence of ischemic stroke during the first month after an acute MI in an unselected population, to identify predictors of MI-related stroke, and to investigate the secular trend in MI-related stroke incidence.

METHODS

In this case-control study, from a population of approximately 310000 25- to 74-year-old inhabitants, case subjects with a stroke within 1 month after an MI were prospectively recorded in the population-based Northern Sweden MONICA (Monitoring of Trends and Determinants in Cardiovascular Disease) study from 1985 to 1994. The same number of control subjects with an MI but without a stroke were matched for age, sex, and year when MI occurred.

RESULTS

One hundred twenty-four case subjects were recorded. Fifty-one percent (63/124) of the strokes occurred within 5 days after onset of MI. The odds ratios (ORs) of an MI-related stroke were for a history of hypertension 1.7 (95% confidence interval [CI], 1.0 to 3.2), previous stroke 2.4 (CI, 1.0 to 6.1), chronic atrial fibrillation 3.0 (CI, 1.1 to 9.2), onset of atrial fibrillation during the hospital stay 3.5 (CI, 1.4 to 10.1), ST-segment elevation 2.4 (CI, 1.4 to 4.6), and anterior infarction 1.5 (CI, 0.9 to 2.6). In a conditional multiple logistic regression model, previous stroke (OR, 2.8; CI, 1.1 to 7.6), chronic atrial fibrillation (OR, 3.8; CI, 1.3 to 11.0), new-onset atrial fibrillation (OR, 4.6; CI, 1.6 to 12.8), and ST-segment elevation (OR, 3.4; CI, 1.6 to 7.4) were independent predictors of stroke. MIs preceding stroke were larger and in 51% were located anteriorly. There was a decrease in the incidence and event rate of MI-related stroke during the study period (P < .01 and P < .05, respectively).

CONCLUSIONS

The risk of stroke is highest the first 5 days after MI. Only approximately half of the strokes occurring the first month after an MI are preceded by an anterior MI. The most important predictors of MI-related stroke are atrial fibrillation (chronic or new onset), ST elevation, and a history of a previous stroke. There is a long-term trend toward a lower incidence of MI-related stroke. These findings have important implications concerning both the pathophysiology and prevention of MI-related stroke.

Cardioembolic stroke

Cardioembolic stroke accounts for 1 out of every 5 to 6 ischemic strokes. A potential cardiac source should be considered in all patients presenting with ischemic neurologic deficits. a clear understanding of the various types of cardiac conditions associated with cardioembolic stroke is important. This article reviews potential cardiac sources of emboli and discusses the role of anticoagulation in both primary and secondary prevention of cardioembolic stroke. The role of echocardiography in evaluating patients with possible cardioembolic stroke is also addressed, and an algorithm is proposed for the use of echocardiography in evaluating patients with ischemic neurologic deficits.