Contemporary Approach to the Diagnosis and Management of Non–ST-Segment Elevation Acute Coronary Syndromes

Vulnerable Plaques Producing an Acute Coronary Syndrome Exhibit a Different CT Phenotype than Those That Remain Silent

Background: All plaques that trigger acute coronary syndromes (ACS) present various characteristics of vulnerability. However, not all vulnerable plaques (VP) lead to an ACS. This raises the question as to which of the established CT vulnerability features hold the highest probability of developing ACS.

Aim: To identify the distinct phenotype of VP that exposes the unstable atheromatous plaque to a higher risk of rupture.

Material and Methods: In total, 20 patients in whom cardiac computed tomographic angiography (CCTA) identified the presence of a vulnerable plaque and who developed an ACS within 6 months after CCTA examination were enrolled in the study, and compared to 20 age- and gender-matched subjects with VPs who did not develop an ACS. All included patients presented VPs at baseline, defined as the presence of minimum 50% degree of stenosis and at least one CT marker of vulnerability (low attenuation plaques [LAP], napkin-ring sign [NRS], positive remodeling [PR], spotty calcifications [SCs]).

Results: The two groups were not different in regards to age, gender, cardiovascular risk factors, and comorbidities. Patients who developed an ACS at six months presented higher volumes of lipid-rich (p = 0.01) and calcified plaques (p = 0.01), while subjects in the control group presented plaques with a larger fibrotic content (p = 0.0005). The most frequent vulnerability markers within VPs that had triggered ACS were LAPs (p <0.0001) and PR (p <0.0001). Multivariate analysis identified LAP as the strongest independent predictor of ACS at 6 months in our study population (OR 8.18 [1.23-95.08], p = 0.04).

Conclusions: VPs producing an ACS exhibit a different phenotype compared to VPs that remain silent. The CCTA profile of VPs producing an ACS includes the presence of low attenuation, positive remodeling, and lipid-rich atheroma. The presence of these features in VPs identifies very high-risk patients, who can benefit from adapted therapeutic strategies in order to prevent an ACS.

Cardiac Computed Tomography Assessment in Acute Coronary Syndromes — Do We Have Time for It in Emergency Settings?

The diagnosis and treatment of acute coronary syndrome remain a challenge for clinicians in many clinical settings, especially in patients with previous low-to-intermediate risk. Due to its high specificity and sensitivity for detecting significant coronary artery stenoses, cardiac computed tomography angiography (CCTA) tends to be used more frequently in the emergency room (ER) in the last years. This technique has been associated with a higher rate of safe discharge in patients with chest pain, less time spent in the ER, and decreased costs related to further investigations. In cases positive for coronary artery stenosis, CCTA can accurately evaluate the indication for percutaneous coronary angioplasty and can offer relevant information related to the characteristics of the coronary plaques, being able to detect vulnerable coronary plaques. The aim of this manuscript is to highlight the possibility of using CCTA in the ER in the assessment of patients with chest pain and to show the benefits of the procedure regarding safety, costs, accuracy, and time.

Association between preprocedural hemoglobin level and 1-year outcome of elective percutaneous coronary intervention

AIM

To evaluate the association between the preprocedural hemoglobin (Hb) level and 1 year major adverse cardiac event (MACE) in patients undergoing percutaneous coronary intervention (PCI).

METHODS

A total of 2819 patients (mean age 56.61 ± 10.37 years, 69% male) with available preprocedural Hb levels were included. Patients were followed up for 12 months. MACE included cardiac death, myocardial infarction (MI), target vessel revascularization and target lesion revascularization. MACE was compared across the different levels of Hb in nonanemic, mild, moderate, and severe anemia subgroups.

RESULTS

The preprocedural mean Hb level was 13.56 ± 1.67 g/dl. Anemic patients were older, more frequently women, and less likely to be cigarette smokers compared to the nonanemic group. Patients with Hb less than 10  mg/dl had the highest proportion of renal failure (56.7%) compared to 40.1% in moderate, 34.6% in mild, and 22.7% in nonanemic groups. In-hospital MI and death occurred in 8 (0.3%) and 2 (0.1%) of the nonanemic group, respectively, and 1 (0.3%) patient with mild anemia experienced MI. After 12 months the rate of total MACE was 3.4% in all the patients. After adjustment for age, sex, interaction between sex, and Hb level, smoking, hypertension, diabetes mellitus, and creatinine clearance, only severe anemia with Hb below 10  g/dl was associated with an increased risk of MACE (hazard ratio 4.623; 95% confidence interval 1.642-13.021; P = 0.004).

CONCLUSION

The impact of anemia on the 12-month MACE was more prominent in patients with Hb below 10  mg/dl. Therefore, in patients with severe anemia listed for PCI, this level of Hb should be considered as a precaution.

Thrombosis of bare metal and patent drug eluting stent in patient operated for colorectal carcinoma: the utility of new guidelines in patients with malignancy

Percutaneous coronary intervention with stent placement is widely used to achieve revascularization of the myocardium, especially in acute coronary syndrome. There is increasing number of reports published concerning stent thrombosis both in bare metal stents as in drug eluting stents. According to the newest ACC/AHA/SCAI 2007th guidelines, bare-metal stent or balloon angioplasty is recommended as an optimal solution if surgery is to be performed in 6-12 months time after stent placement. We present a case of a 56-year-old male with colon carcinoma who suffered from post-operational myocardial infarction due to bare metal stent thrombosis, while the drug eluting stent remained patent. Currently, in our opinion, high level evidence is lacking in the literature in support for recommendations published in current ACC, AHA and SCAI 2007th guidelines regarding the choice of stent, antiaggregation and anticoagulation therapy. This case, together with others previously published suggests a need for development of an applicable strategy for selection and treatment of patients with increased perioperative risk of in-stent thrombosis in order to ensure optimal medical treatment.

Current Trends in Diagnostic Biomarkers of Acute Coronary Syndrome

The diagnosis and management of patients with acute coronary syndrome (ACS) have evolved dramatically over the past decade. Biomarkers play an important role in the diagnosis of ACS, especially in unstable angina and non-ST-segment elevation myocardial infarction. Among these, cardiac troponin and creatine kinase appear to be the most sensitive and specific markers of myocardial injury. Recent studies have revealed several novel biomarkers. Elevated levels of C-reactive protein and interleukin-6 are strong independent markers of increased mortality among patients with ACS. However, the ideal biomarkers that offer early detection, risk stratification, selection of therapy, monitoring disease progression, and treatment efficacy remain to be elucidated. This review assesses limitations and contemporary needs for biomarkers in the context of diagnosis of ACS. It also discusses the newly developing technologies for novel biomarkers or novel biomarker protein signatures discovery, and importance of point-of-care testing for future management. Key words: Cardiac troponin, Creatine kinase, NSTEMI