Predictors of coronary artery disease in patients with cocaine-associated myocardial infarction. Cocaine-Associated Myocardial Infarction (CAMI) Study Group

Heightened risk of cardiac events following percutaneous coronary intervention for cocaine-associated myocardial infarction

INTRODUCTION

Several works have suggested heightened risk for cardiac events in cocaine users following percutaneous coronary intervention (PCI). Such studies have generally been performed in small, poorly defined samples and have not utilised optimal control groups. We aimed to define the short-term risk for death or recurrent myocardial infarction (MI) when PCI was performed for myocardial infarction in subjects presenting with urine toxicology positive for cocaine in relation to subjects testing negative for cocaine use.

MATERIAL AND METHODS

Our institutional electronic health record (EHR) was queried for all subjects with urine toxicology performed for cocaine exposure within 5 days before or after having elevated troponin-T assay between 1/1/08 and 12/31/13. Query results were cross-referenced with our institutional cardiology database to identify the sample who had PCI on the same admission as the cocaine test. Subsequent readmission for MI was assessed from the EHR, and deaths were identified from the National Death Index.

RESULTS

PCI had been performed in 380 subjects who tested negative for cocaine and 44 subjects who tested positive. In the cocaine-positive group, incidences of death or MI at 30 days and 1 year were 18% and 23%, respectively. Those who tested positive for cocaine had increased odds (odds ratio (OR) = 2.3, 95% confidence interval (CI): 1.0-5.1, p = 0.04) for death or MI at 30 days post PCI, after adjustment for age, sex, prior MI, and comorbidity index. Although the odds for events 1-year post PCI were not increased (OR = 2.0, 95% CI: 0.9-4.3), the p-value approached significance in this small sample (p = 0.09).

CONCLUSIONS

This retrospective study suggests that PCI performed in cocaine-associated myocardial infarction comes with a high 30-day and one-year risk. Further prospective studies are needed to better define this risk and to lend insight into better management strategies.

S100B protein expression in the heart of deceased individuals by overdose: a new forensic marker?

OBJECTIVE

The evaluation of S100B protein expression in the human heart and its correlation with drug-related death.

METHOD

Left ventricular samples were collected from 74 serial forensic autopsies (15 overdose-related deaths; 59 non-overdose-related deaths) from 2007 to 2010. Tissue sections from each sample were immunostained for S100B protein by a commercial antibody.

RESULTS

The S100B protein was detected in the heart samples of all 15 cases of drug-related deaths; S100B immunoreactivity was mainly observed in the cytoplasm of cardiomyocytes and as globular deposits in the interstitial spaces. No reactivity or weak reactivity was found in the cardiomyocytes of the 59 subjects who died of other causes.

CONCLUSION

Our preliminary data show that the S100B protein accumulates in injured cardiomyocytes during drug-related sudden death. Given the near absence of S100B protein in the heart of subjects who died from causes other than drug overdose, S100B immunopositivity may be used as a new ancillary screening tool for the postmortem diagnosis of overdose-related cardiac death.

Relationship between cocaine use and coronary artery disease in patients with symptoms consistent with an acute coronary syndrome

OBJECTIVES

Observational studies of patients with cocaine-associated myocardial infarction have suggested more coronary disease than expected on the basis of patient age. The study objective was to determine whether cocaine use is associated with coronary disease in low- to intermediate-risk emergency department (ED) patients with potential acute coronary syndrome (ACS).

METHODS

The authors conducted a cross-sectional study of low- to intermediate-risk patients<60 years of age who received coronary computerized tomographic angiography (CTA) for evaluation of coronary artery disease (CAD) in the ED. Patients were classified into three groups with respect to CAD: maximal stenosis <25%, 25% to 49%, and ≥50%. Prespecified multivariate modeling (generalized estimating equations) was used to assess relationship between cocaine and CAD.

RESULTS

Of 912 enrolled patients, 157 (17%) used cocaine. A total of 231 patients had CAD ≥25%; 111 had CAD ≥50%. In univariate analysis, cocaine use was not associated with a lesion 25% or greater (12% vs. 14%; relative risk [RR]=0.89, 95% confidence interval [CI]=0.5 to 1.4) or 50% or greater (12% vs. 11%; RR=1.15, 95% CI=0.6 to 2.3). In multivariate modeling adjusting for age, race, sex, cardiac risk factors, and Thrombosis in Myocardial Infarction (TIMI) score, cocaine use was not associated with the presence of any coronary lesion (adjusted RR=0.95, 95% CI=0.69 to 1.31) or coronary lesions 50% or greater (adjusted RR=0.78, 95% CI=0.45 to 1.38). There was also no relationship between repetitive cocaine use and coronary calcifications or between recent cocaine use and CAD.

CONCLUSIONS

In symptomatic ED patients at low to intermediate risk of an ACS, cocaine use was not associated with an increased likelihood of coronary disease after adjustment for age, race, sex, and other risk factors for coronary disease.

The utility of the initial electrocardiogram in predicting acute coronary events in current cocaine users with chest pain in the emergency department

INTRODUCTION

Chest pain suggestive of myocardial ischemia or infarction is a common emergency department complaint and a subset of these is associated with cocaine use. It can be difficult to triage patients with chest pain while using cocaine.

OBJECTIVE

To assess the reliability of the initial electrocardiogram (ECG) done in the emergency department in current cocaine users suspected of acute coronary syndrome (ACS) in predicting a true event.

METHODS

A total of 218 charts of current cocaine users who presented with chest pain judged as possibly cardiac in nature with an initial ECG from September 2003 to August 2007 were reviewed. Initial ECG was classified into: (1) Category A (inverted T waves in two or more contiguous leads and/or characteristic ST segment elevation or depression indicative of an ischemic event possibly acute); (2) Category B (other ischemic changes but without any ST or T abnormalities such as Q wave, or bundle branch block); or (3) Category C (normal tracing, non-specific ST segment or T wave alterations).

RESULTS

Eighteen of 218 (8.3%) were confirmed to have ACS. Ten of 18 confirmed ACS patients were among the 70 cases with ECG classified as Category A. One hundred and one of 218 were Category C ECGs: five of these had ACS (three of the five had significant cardiac history) and 96 did not, consistent with 95% negative predictive value. Patients with Category A ECG characteristics were three times at risk to have ACS compared with a Category C ECG.

CONCLUSION

The initial ECG with a good clinical history can be used effectively to triage patients presenting with chest pain and current use of cocaine in the emergency department.

Coronary computerized tomography angiography for rapid discharge of low-risk patients with cocaine-associated chest pain

BACKGROUND

Most patients presenting to emergency departments (EDs) with cocaine-associated chest pain are admitted for at least 12 hours and receive a "rule out acute coronary syndrome" protocol, often with noninvasive testing prior to discharge. In patients without cocaine use, coronary computerized tomography angiography (CTA) has been shown to be useful for identifying a group of patients at low risk for cardiac events who can be safely discharged. It is unclear whether a coronary CTA strategy would be efficacious in cocaine-associated chest pain, as coronary vasospasm may account for some of the ischemia. We studied whether a negative coronary CTA in patients with cocaine-associated chest pain could identify a subset safe for discharge.

METHODS

We prospectively evaluated the safety of coronary CTA for low-risk patients who presented to the ED with cocaineassociated chest pain (self-reported or positive urine test). Consecutive patients received either immediate coronary CTA in the ED (without serial markers) or underwent coronary CTA after a brief observation period with serial cardiac marker measurements. Patients with negative coronary CTA (maximal stenosis less than 50%) were discharged. The main outcome was 30-day cardiovascular death or myocardial infarction.

RESULTS

A total of 59 patients with cocaine-associated chest pain were evaluated. Patients had a mean age of 45.6 +/- 6.6 yrs and were 86% black, 66% male. Seventy-nine percent had a normal or nonspecific ECG and 85% had a TIMI score <2. Twenty patients received coronary CTA immediately in the ED, 18 of whom were discharged following CTA (90%). Thirty-nine received coronary CTA after a brief observation period, with 37 discharged home following CTA (95%). Six patients had coronary stenosis >or=50%. During the 30-day follow-up period, no patients died of a cardiovascular event (0%; 95% CI, 0-6.1%) and no patient sustained a nonfatal myocardial infarction (0%; 95% CI, 0-6.1%).

CONCLUSIONS

Although cocaine-associated myocardial ischemia can result from coronary vasoconstriction, patients with cocaine associated chest pain, a non-ischemic ECG, and a TIMI risk score <2 may be safely discharged from the ED after a negative coronary CTA with a low risk of 30-day adverse events.

Cocaine use and hypertensive renal changes in HIV-infected individuals

BACKGROUND AND OBJECTIVES

Cocaine causes kidney damage, but data linking cocaine use to chronic kidney disease in HIV patients is not described. This study was conducted to evaluate the possible association of cocaine use and histopathologic findings on biopsy in this population.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Kidney biopsies that were performed in HIV-infected patients during the course of 11 yr were reviewed. Demographic and clinical data were collected. Hypertensive changes were defined on the basis of the Banff 97 classification. Criteria of both arterial intimal fibrosis and thickening and hyaline arteriolosclerosis were used and graded as absent (0), mild (1), moderate (2), and severe (3). Hypertensive renal changes were considered present when the combined pathology score was > or = 2. To minimize confounding, those with hypertension or diabetes were excluded.

RESULTS

Of the 193 HIV patients who underwent kidney biopsy, 53 had no history of hypertension or diabetes with HIV infection. Of those, 29 (55%) had hypertensive renal changes on kidney biopsy. Cocaine use was present in 16 (55%) of 29 with hypertensive renal changes compared with six (25%) of 24 without hypertensive renal changes (odds ratio [OR] 3.7; 95% confidence interval [CI] 1.2 to 11.7). In the adjusted analyses, only age (/yr; OR 1.08; 95% CI 1.00 to 1.16) and cocaine use (OR 3.55; 95% CI 1.04 to 12.14) were significantly associated with hypertensive renal changes on renal biopsy.

CONCLUSIONS

Cocaine use is associated with hypertensive renal changes in HIV-infected patients in the absence of hypertension and diabetes.

Cocaine-induced acute myocardial infarction

Acute myocardial infarction may occur following cocaine use. Cocaine-induced infarction is particularly common in younger patients aged 18 to 45 years old. Patients may or may not have angiographic evidence of coronary artery disease at the time of their acute event. Previous studies have shown that coronary artery spasm occurs with cocaine use, and perhaps platelet activation, both contributing to a process that may culminate in coronary artery occlusion. Primary coronary intervention should be the preferred revascularization modality by an experienced team. Thrombolytic therapy needs to be instituted if this intervention is unavailable. Beta blockers should be utilized with caution since they may increase coronary spasm or cause a paradoxical rise in blood pressure. They should be avoided in the early hours of the infarction, but be instituted prior to patient discharge. Interruption of cocaine abuse is the cornerstone of secondary prevention in cocaine-related myocardial infarction.

Increased incidence of stent thrombosis in patients with cocaine use

INTRODUCTION

Coronary stent thrombosis is a rare occurrence in the era of dual-antiplatelet therapy. It is not known whether patients who use cocaine have a higher risk of thrombosis following coronary stent placement.

METHODS

We studied 247 consecutive patients who underwent coronary stent placement at an inner-city hospital.

RESULTS

Twelve patients (4.9%) were actively using cocaine at the time of PCI. Of these twelve patients, four patients presented with stent thrombosis (33%) at a mean of 51 +/- 40 days (median 45 days), after the index revascularization procedure. Only 2 of the 235 patients without documented cocaine use (0.85%) had stent thrombosis during the same period (P < 0.0001).

CONCLUSION

The patients who actively use cocaine have a markedly higher risk of stent thrombosis when compared with patients without a documented history of cocaine use. We discuss various factors that potentially predispose cocaine users to stent thrombosis.

Comparative cardiac pathology among deaths due to cocaine toxicity, opioid toxicity and non-drug-related causes

AIM

To compare cardiac and cerebrovascular pathology among deaths due to cocaine toxicity, deaths due to opioid toxicity and deaths from hanging that were toxicologically negative for cocaine/opioids.

DESIGN

Case-control.

FINDINGS

The cocaine group had significantly higher proportions of left ventricular hypertrophy and ischaemic heart disease than either comparison group. Coronary artery atherosclerosis was also detected in significantly higher proportions of cocaine cases than in either comparison group. The cocaine group was more likely than either comparison group to have atherosclerosis of the left anterior descending coronary artery, right coronary artery and circumflex artery. Only in the left anterior descending coronary artery did the cocaine group exhibit higher levels of moderate-severe atherosclerosis. Cocaine cases also had significantly higher levels of cerebrovascular atherosclerosis than either comparison group.

CONCLUSIONS

Levels of cardiac and cerebrovascular pathology were higher among cocaine users than either comparison group. The high levels of cardiac and cerebrovascular pathology seen among cocaine cases do not appear to be artefacts of a drug-dependent life-style, but relate specifically to cocaine.

Cocaine-related fatalities in New South Wales, Australia 1993-2002

AIM

To ascertain the demographic characteristics, circumstances of death, toxicological results, and major autopsy findings of cocaine-related fatalities.

DESIGN

Inspection of the coronial records of all cocaine-related deaths that occurred in New South Wales, Australia between 1 January 1993 and 31 December 2002.

SETTING

New South Wales, Australia.

FINDINGS

146 cases were identified. Cocaine was implicated in the direct cause of death in 86% of cases, an antecedent cause in 8% and a significant condition contributing to death in 7%. The mean age of decedents was 34.1 years, and 84% were male. Half were employed, and 26% were in professional employment. The predominant route of administration was injection (86%), however nasal (8%), oral (3%), smoking (1%), and anal (1%) administration were all recorded. The most common location of death was a private home (53%). No intervention occurred prior to death in 82% of cases. The median blood benzoylecgonine concentration was 0.40 mg/L (range 0.00-20.00 mg/L). Cases had a mean of 3.5 drugs, with morphine (79%) the most common co-occurring drug. In 5% of cases cocaine was the sole drug detected. Cardiac pathology was noted in 57% of cases, most commonly coronary artery atherosclerosis (39%) and cardiac hypertrophy (14%). In 15% of cases moderate to severe arterial occlusion was noted. Cerebrovascular pathology was noted in 22% of cases, most commonly cerebrovascular atherosclerosis (10%).

CONCLUSIONS

Cocaine-related deaths are a significant clinical problem in New South Wales.

Cardiovascular manifestations of substance abuse part 1: cocaine

Substance abuse with cocaine is associated with multiple cardiovascular conditions, including myocardial infarction, dissection, left ventricular hypertrophy, arrhythmias, sudden death, and cardiomyopathy. Cocaine has effects to potentiate the physiologic actions of catecholamines and has direct effects on voltage-dependent sodium ion channels related to local anesthetic properties. The effects of cocaine can be augmented with concomitant alcohol consumption. Acute myocardial ischemia caused by cocaine may be related to in situ thromboisis and/or coronary vasospasm. Treatment strategies for cocaine-induced myocardial infarction would include antiplatelet therapy, thrombolysis, and vasodilators (eg, nitrates, nifedipine). Beta-adrenergic blockers should not be used unless concomitant vasodilator therapy is given.

Coronary angiographic findings in patients with cocaine-associated chest pain

Patients who present to the Emergency Department (ED) with chest pain associated with cocaine use are a common problem. The incidence and predictors of underlying significant coronary disease in patients with and without myocardial infarction (MI) has not been well described. Patients who underwent coronary angiography within 5 weeks of an ED evaluation for cocaine-associated chest pain were studied. Significant disease was defined as > or = 50% stenosis of a coronary artery or major branches or bypass graft. A total of 90 patients underwent coronary angiography. Significant disease was present in 45 (50%), with 1-vessel disease in 32%, 2-vessel disease in 10%, 3-vessel disease in 6%, with significant graft stenosis in 3%. Significant disease was present in 77% of patients with MI or troponin I elevations, compared to only 35% of patients without myonecrosis. Predictors of significant coronary disease included MI or troponin I elevations, prior MI, known coronary disease (prior MI or revascularization), and elevated cholesterol. Only 7 of the 39 patients (18%) without myonecrosis or a history of coronary disease had significant disease on angiography. In conclusion, significant disease is found in the majority of patients with cocaine-associated MI or troponin elevations. In contrast, only a minority of those without myonecrosis have significant coronary disease.

Quantitative comparison of coronary artery flow and myocardial perfusion in patients with acute myocardial infarction in the presence and absence of recent cocaine use

BACKGROUND

Numerous factors have been implicated in the pathogenesis of cocaine associated myocardial infarction (CAMI). However, the relative contributions each of these mechanisms provide to the pathogenesis of CAMI have not been well defined. We hypothesized that significant angiographic differences exist between CAMI patients vs thrombotic AMI patients (TAMI) and normal controls.

METHODS

The TIMI Flow Grade, corrected TIMI Frame Count (CTFC), TIMI Myocardial Perfusion Grade (TMPG), presence of triple-vessel disease, stenosis severity, and presence of angiographically apparent thrombus were compared in patients who sustained CAMI to TAMI patients and normal controls.

RESULTS

2495 angiograms were analyzed (CAMI = 57, TAMI = 2403, Controls = 35). Impairment in both epicardial and microvascular flow in patients with CAMI was intermediate between TAMI and controls. Compared to TAMI patients, CAMI patients were less likely to have 3 vessel disease (8.9% vs. 19.1%; p < 0.05), epicardial stenosis was less severe (14.9+/-30.2 vs. 72.6+/-18.6; p < 0.0001), less thrombus was present (6.5% vs. 33.1%; p < 0.001) and TIMI grade 3 flow was observed more frequently (76% vs. 59%). Normal TMPG 3 perfusion was significantly impaired in both CAMI and TAMI patients when compared to controls without AMI (TMPG 3 was 40% and 26.6% vs. 100% respectively; p < 0.001 for both). The majority of patients in both AMI groups had diminished or absent tissue level perfusion (TMPG 0 flow, CAMI 53.9 vs. TAMI 56.8%).

CONCLUSIONS

Both epicardial and microvascular flow is impaired in CAMI. While epicardial flow among CAMI patients is slightly better than TAMI patients, the incidence of little or severely impaired tissue level perfusion is nearly identical.