Ivan Pena-Sing

Mechanisms of Myocardial Infarction in Women Without Angiographically Obstructive Coronary Artery Disease

Background— There is no angiographically demonstrable obstructive coronary artery disease (CAD) in a significant minority of patients with myocardial infarction, particularly women. We sought to determine the mechanism(s) of myocardial infarction in this setting using multiple imaging techniques. Methods and Results— Women with myocardial infarction were enrolled prospectively, before angiography, if possible. Women with ≥50% angiographic stenosis or use of vasospastic agents were excluded. Intravascular ultrasound was performed during angiography; cardiac magnetic resonance imaging was performed within 1 week. Fifty women (age, 57±13 years) had median peak troponin of 1.60 ng/mL; 11 had ST-segment elevation. Median diameter stenosis of the worst lesion was 20% by angiography; 15 patients (30%) had normal angiograms. Plaque disruption was observed in 16 of 42 patients (38%) undergoing intravascular ultrasound. There were abnormal myocardial cardiac magnetic resonance imaging findings in 26 of 44 patients (59%) undergoing cardiac magnetic resonance imaging, late gadolinium enhancement (LGE) in 17 patients, and T2 signal hyperintensity indicating edema in 9 additional patients. The most common LGE pattern was ischemic (transmural/subendocardial). Nonischemic LGE patterns (midmyocardial/subepicardial) were also observed. Although LGE was infrequent with plaque disruption, T2 signal hyperintensity was common with plaque disruption. Conclusions— Plaque rupture and ulceration are common in women with myocardial infarction without angiographically demonstrable obstructive coronary artery disease. In addition, LGE is common in this cohort of women, with an ischemic pattern of injury most evident. Vasospasm and embolism are possible mechanisms of ischemic LGE without plaque disruption. Intravascular ultrasound and cardiac magnetic resonance imaging provide complementary mechanistic insights into female myocardial infarction patients without obstructive coronary artery disease and may be useful in identifying potential causes and therapies. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00798122.

Sex and Race Are Associated With the Absence of Epicardial Coronary Artery Obstructive Disease at Angiography in Patients With Acute Coronary Syndromes

A substantial minority of patients with acute coronary syndromes (ACS) do not have a diameter stenosis of any major epicardial coronary artery on angiography (“no obstruction at angiography”) of ≥ 50%. We examined the frequency of this finding and its relationship to race and sex.

Favorable Effects of Insulin Sensitizers Pertinent to Peripheral Arterial Disease in Type 2 Diabetes: Results from the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial

OBJECTIVE The aim of this manuscript was to report the risk of incident peripheral arterial disease (PAD) in a large randomized clinical trial that enrolled participants with stable coronary artery disease and type 2 diabetes and compare the risk between assigned treatment arms. RESEARCH DESIGN AND METHODS The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial randomly assigned participants to insulin sensitization (IS) therapy versus insulin-providing (IP) therapy for glycemic control. Results showed similar 5-year mortality in the two glycemic treatment arms. In secondary analyses reported here, we examine the effects of treatment assignment on the incidence of PAD. A total of 1,479 BARI 2D participants with normal ankle-brachial index (ABI) (0.91–1.30) were eligible for analysis. The following PAD-related outcomes are evaluated in this article: new low ABI ≤0.9, a lower-extremity revascularization, lower-extremity amputation, and a composite of the three outcomes. RESULTS During an average 4.6 years of follow-up, 303 participants experienced one or more of the outcomes listed above. Incidence of the composite outcome was significantly lower among participants assigned to IS therapy than those assigned to IP therapy (16.9 vs. 24.1%; P < 0.001). The difference was significant in time-to-event analysis (hazard ratio 0.66 [95% CI 0.51–0.83], P < 0.001) and remained significant after adjustment for in-trial HbA1c (0.76 [0.59–0.96], P = 0.02). CONCLUSIONS In participants with type 2 diabetes who are free from PAD, a glycemic control strategy of insulin sensitization may be the preferred therapeutic strategy to reduce the incidence of PAD and subsequent outcomes.

Ankle-brachial index and cardiovascular outcomes in the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial

BACKGROUND Peripheral arterial disease increases cardiovascular risk in many patient populations. The risks associated with an abnormal ankle-brachial index (ABI) in patients with type 2 diabetes and stable coronary artery disease have not been well described with respect to thresholds and types of cardiovascular events. METHODS We examined 2,368 patients in the BARI 2D trial who underwent ABI assessment at baseline. Death and major cardiovascular events (death, myocardial infarction and stroke) during follow-up (average 4.3 years) were assessed across the ABI spectrum and by categorized ABI: low (≤0.90), normal (0.91-1.3), high (>1.3), or noncompressible. RESULTS A total of 12,568 person-years were available for mortality analysis. During follow-up, 316 patients died, and 549 had major cardiovascular events. After adjustment for potential confounders, with normal ABI as the referent group, a low ABI conferred an increased risk of death (relative risk [RR] 1.6, CI 1.2-2.2, P = .0005) and major cardiovascular events (RR 1.4, CI 1.1-1.7, P = .004). Patients with a high ABI had similar outcomes as patients with a normal ABI, but risk again increased in patients with a noncompressible ABI with a risk of death (RR 1.9, CI 1.3-2.8, P = .001) and major cardiovascular event (RR 1.5, CI 1.1-2.1, P = .01). CONCLUSIONS In patients with coronary artery disease and type 2 diabetes, ABI screening and identification of ABI abnormalities including a low ABI (<1.0) or noncompressible artery provide incremental prognostic information.

Characteristics of plaque disruption by intravascular ultrasound in women presenting with myocardial infarction without obstructive coronary artery disease

BACKGROUND In a prospective study, we previously identified plaque disruption (PD: plaque rupture or ulceration) in 38% of women with myocardial infarction (MI) without angiographically obstructive coronary artery disease (CAD), using intravascular ultrasound (IVUS). Underlying plaque morphology has not been described in these patients and may provide insight into the mechanisms of MI without obstructive CAD. METHODS Forty-two women with MI and <50% angiographic stenosis underwent IVUS (n = 114 vessels). Analyses were performed by a blinded core laboratory. Sixteen patients had PD (14 ruptures and 5 ulcerations in 18 vessels). Plaque area, % plaque burden, lumen area stenosis, eccentricity, and remodeling index were calculated for disrupted plaques and largest plaque by area in each vessel. RESULTS Disrupted plaques had lower % plaque burden than the largest plaque in the same vessel (31.9% vs 49.8%, P = .005) and were rarely located at the site of largest plaque (1/19). Disrupted plaques were typically fibrous and were not more eccentric or remodeled than the largest plaque in the same vessel. CONCLUSIONS Plaque disruption was often identifiable on IVUS in women with MI without obstructive CAD. Plaque disruption in this patient population occurred in fibrous or fibrofatty plaques and, contrary to expectations based on prior studies of plaque vulnerability, did not typically occur in eccentric, outwardly remodeled, or soft plaque in these patients. Plaque disruption rarely occurred at the site of the largest plaque in the vessel. These findings suggest that the pathophysiology of PD in women with MI without angiographically obstructive CAD may be different from MI with obstructive disease and requires further investigation.

Prospective evaluation of the use and outcome of admission stool guaiac testing: the Digital Rectal Examination on Admission to the Medical Service (DREAMS) Study.

Background Although physicians often perform fecal occult blood testing at the time of hospital admission, the practice of admission stool guaiac (ASG) testing has not been evaluated prospectively. The aim of this study was to determine the frequency and outcomes of digital rectal examination (DRE) and ASG testing in patients admitted to the hospital. Methods We prospectively evaluated 2143 patients admitted to the medical service at our hospital over a 1-year period. A detailed clinical history was obtained, and the proportion of patients who had DRE and ASG testing, the frequency of positive tests, and the results of follow-up testing were determined. Results A DRE was performed in 1539 of the 2143 subjects (71.8%), and 1.8% had abnormal findings, 21.8% had a normal examination, and the result of ASG testing was the only documented finding in the remaining 76.4% of patients. ASG testing was performed in 1342 of the 2143 subjects (62.6%), and the ASG test was positive in 237 persons (17.7%). However, only 161 (67.9%) of those with a positive ASG test had further diagnostic testing and a colonic source of occult gastrointestinal blood loss was detected in 68 (42.2%) of these 161 persons. Conclusions Although DRE and ASG testing are commonly performed on admission to the hospital, documentation of the findings and follow-up of positive tests are poor. These findings highlight the need to improve physician training on the appropriate use and documentation of the DRE and fecal occult blood testing.

Bivalirudin reduces hemorrhagic complications and glycoprotein IIB/IIIA inhibitor usage in coronary intervention: Results from the NYU bivalirudin registry

Adjusted Rates of Primruy PC1 Use (% of all AM1 Patients) 1005A-219 Bivalirudin Reduces Hemorrhagic Complications and Glycoprotein IlBllllA Inhibitor Usage in Coronary Intervention: Results From the NYU Bivalirudin Registry Country (Province) 199

Response to Letters Regarding Article, “Mechanisms of Myocardial Infarction in Women Without Angiographically Obstructive Coronary Artery Disease”

Dr Ward suggests that plaque ruptures identified by the core laboratory in our study1 were not responsible for troponin elevation and instead had a nonischemic cause, and that these plaque ruptures may have been caused by intravascular ultrasound. We respectfully disagree. We believe that the observed ruptured plaques were responsible for troponin elevation in patients in this study for several reasons. First, all patients presented with acute onset of ischemic symptoms, and we find it very unlikely that plaque rupture is incidental in this setting. We acknowledge that it is impossible to exclude plaque rupture caused by the intravascular ultrasound procedure in this or any study using intravascular ultrasound. Though we did not include stable control patients, …