Features of disrupted plaques by coronary computed tomographic angiography: correlates with invasively proven complex lesions.

BACKGROUND: This study was designed as a "proof-of-concept" to establish whether coronary computed tomographic angiography (CTA) has the capability to identify morphological features of plaque disruption. METHODS AND RESULTS: In patients with unstable angina undergoing CTA and invasive coronary angiography within 30 days, quantitative CTA analysis was performed on all plaques for percent stenosis, volume, remodeling index, and volume of low-attenuation plaque (<50 Hounsfield units). Plaques with >25% stenosis were evaluated for CTA features of disruption, including ulceration and intraplaque dye penetration. Using invasive coronary angiography complex plaque as the reference standard for disruption, the sensitivity and specificity of ulceration and intraplaque dye penetration by CTA were determined. In 60 patients, 294 plaques were identified by CTA, of which 109 (37%) had features of disruption, including ulceration in 53 (18%) lesions and intraplaque dye penetration in 80 (27%). Compared with nondisrupted lesions, plaques with ulceration or intraplaque dye penetration by CTA were more voluminous (313±356 mm(3) versus 118±93 mm(3) P<0.0001), more often positively remodeled (94.5% versus 44.3%, P<0.0001), contained more low-attenuation plaque (99±161 mm(3) versus 19±18 mm(3), P<0.0001), and were more often complex by ICA (57.8% versus 8.1%, P<0.0001). CTA features of disruption demonstrated modest to good sensitivity (53% to 81%) and good specificity (82% to 95%) for complex plaque by invasive coronary angiography. CONCLUSIONS: In this highly selected group of patients with unstable angina, CTA can delineate features of plaque disruption, including ulceration and intraplaque dye penetration, which are specific markers of invasively identified complex plaque. Further studies are needed to confirm the generalizability of the results and to explore the clinical and prognostic implications of these findings.

CHADS(2) score is predictive of left atrial thrombus on precardioversion transesophageal echocardiography in atrial fibrillation.

OBJECTIVE: The goals of this study were to determine: 1) if the CHADS(2) score correlates with left atrial (LA) or left atrial appendage (LAA) thrombus on pre-cardioversion transesophageal echocardiography (TEE) in nonvalvular atrial fibrillation (NVAF); and 2) what, if any, components of the CHADS(2) score are most important in predicting LA/LAA thrombus. BACKGROUND: It is unknown if CHADS(2) score, a marker of thromboembolic risk in NVAF, accurately predicts LA/LAA thrombus on pre-cardioversion TEE. METHODS: We retrospectively studied patients undergoing precardioversion TEE for NVAF at a tertiary hospital. TEE reports were reviewed for presence of LA/LAA thrombus. Using medical records and an ICD-9 coding database, a CHADS(2) score was derived, and the association between CHADS(2) and thrombus was evaluated with Mantel-Haenszel Chi-Square. The relation between the singular components of CHADS(2) and thrombus were analyzed using Pearson's Chi-Square. RESULTS: In 643 consecutive patients undergoing pre-cardioversion TEE, LA/LAA thrombus was identified in 46 (7.2 %). A strong association was present between CHADS(2)score and LA/LAA thrombus (p = 0.0005). No thrombi were identified in patients with CHADS(2) = 0. Among 46 patients with thrombus, all (100%) had CHF. Of the singular components, CHF was the only factor independently associated with thrombus (p < 0.0001). CONCLUSIONS: In non-valvular atrial fibrillation, CHADS(2) is strongly associated with LA thrombus on TEE. Our findings suggest pre-cardioversion TEE may be unnecessary if the CHADS(2) score = 0. Of the components of the CHADS(2) score, CHF was the only independently associated risk factor which correlated with LA/LAA thrombus.

Venous thromboembolism in patients hospitalized with thyroid dysfunction.

The objective of this investigation is to explore a possible role of thyroid dysfunction in venous thromboembolism (VTE). The number of patients discharged from short-stay nonfederal hospitals in the United States, from 1979 to 2005, with a diagnostic code for hypothyroidism or hyperthyroidism, pulmonary embolism (PE), and deep venous thrombosis (DVT) was obtained from the National Hospital Discharge Survey (NHDS). Among 19,519,000 hospitalized patients discharged with a diagnosis of hypothyroidism from 1979 to 2005, 119,000 (0.61%) had PE. Among patients with no thyroid dysfunction, PE was diagnosed in 3,372,000 of 908,805,000 patients (0.37%; relative risk = 1.64, 95% CI 1.63-1.65). Deep venous thrombosis was diagnosed in 1.36% of hypothyroid patients and in 0.84% of patients with no thyroid dysfunction (relative risk = 1.62, 95% CI 1.61-1.62). The relative risk of PE in patients with hypothyroidism was highest in patients <40 years of age (relative risk = 3.99) and the relative risk of DVT was also highest in patients <40 years (relative risk = 2.25). Hyperthyroidism was not associated with an increased risk of VTE (relative risk = 0.98, 95% CI = 0.96-1.01). In conclusion, an increased risk of PE, DVT, and VTE was shown in patients with hypothyroidism but not hyperthyroidism. Antithrombotic prophylaxis in patients with severe hypothyroidism, however, should be viewed with caution because of a possible hyperfibrinolytic state in such patients.