Image quality with single-heartbeat 320-multidetector computed tomographic coronary angiography.

OBJECTIVE: We aimed to establish the feasibility of single-heartbeat 320-multidetector computed tomographic coronary angiography (CTCA) and assess variables affecting image quality. METHODS: Consecutive patients (n = 249, 38% male) underwent CTCA. Two observers assessed image quality using a 4-point scale (1, excellent; 4, poor). RESULTS: Mean heart rate was 60 beats per minute (95% confidence interval, 59-62); body mass index, 29 kg/m (28-30); and dose-length product, 283 mGy·cm (266-301). During scanning, 133 (51%) received sublingual glyceryl trinitrate (GTN), 9 (4%) had ectopics, and 12 (5%) had atrial fibrillation. Diagnostic image quality was obtained in 99% with mean image quality of 1.4 (1.3, 1.5). Age, sex, atrial fibrillation, ectopics, diabetes mellitus (12%), and obstructive disease were not related to image quality. A lower heart rate and GTN were associated with improved image quality (P ≤ 0.001). CONCLUSIONS: Optimal image quality in single-heartbeat 320-multidetector CTCA is achievable in 99% of unselected patients. Image quality is improved by lower heart rate and GTN.

Low-dose dobutamine adds incremental value to late gadolinium enhancement cardiac magnetic resonance in the prediction of adverse remodelling following acute myocardial infarction.

AIMS: To examine the relative and combined value of late gadolinium enhancement (LGE) and low-dose dobutamine (LDD) cardiac magnetic resonance (CMR) to predict 'adverse remodelling' (AR) following acute myocardial infarction (AMI). METHODS AND RESULTS: Forty-five patients with AMI were recruited. CMR was performed 2-4 days after presentation and at 6 months. Ventricular wall motion and volume were recorded at rest and following dobutamine infusion. Measures of first pass perfusion, persistent microvascular obstruction (PMO), and LGE were obtained following contrast administration. Quantitation was performed using the MEDIS 6.2 software. Regression analysis was employed to determine the univariables and multivariate models most predictive of AR at 6 months. The incremental and relative value of LDD over LGE was investigated. The most predictive univariable was 'volume of PMO' (r = 0.51, r2 = 0.26, P < 0.001). The optimal 'combined' multivariate model, utilizing data from all components, was highly predictive of AR (r = 0.82, r2 = 0.67, P < 0.001). The optimal model using parameters only from the LGE component also predicted remodelling (r = 0.65, r2 = 42.0, P = 0.001) but with less accuracy. In contrast, the optimal model using variables from the LDD component alone predicted remodelling with a similar accuracy to the optimal combined model (r = 0.82, r2 = 0.67, P < 0.001). CONCLUSION: A comprehensive CMR examination accurately predicts AR following AMI. LDD is superior to LGE CMR in this respect. These data suggest that LDD not only adds incremental value to LGE in the prediction of remodelling post-AMI but also may be utilized alone with the same predictive power.

Noninvasive assessment of left ventricular filling pressure after acute myocardial infarction: a prospective study of the relative prognostic utility of clinical assessment, echocardiography, and B-type natriuretic peptide.

BACKGROUND: Elevated left ventricular filling pressure after acute myocardial infarction (AMI) may be identified using clinical assessment, echocardiography, and B-type natriuretic peptide (BNP) levels. All of these predict outcome in this setting. There are, however, no data assessing their relative prognostic value. The current study addresses this. METHODS: Four hundred patients underwent detailed echocardiography and measurement of BNP levels after AMI (median 1 day). The study end points were (1) a composite of death, recurrent AMI, and/or admission to hospital with heart failure within 1 year and (2) all-cause mortality during medium-term follow-up (median 2.9 years). RESULTS: Both an elevated ratio of early transmitral flow to early mitral annulus velocity (E/e') and higher BNP levels were associated with an increased risk of an adverse event within the first year (odds ratio 6.14 for E/e' >15, P < .001; odds ratio 1.19 per 50-pg/mL increase in BNP, P < .001) and medium-term mortality (hazard ratio 4.67 for E/e' >15, P < .001; hazard ratio 1.10 per 50-pg/mL increase in BNP, P < .001). Among patients with BNP levels higher than the median or in the upper quartile, an E/e' ratio >15 identified a subgroup at greatest risk of mortality (P < .001 for both). CONCLUSIONS: The E/e' ratio and BNP levels play important and complementary roles in the risk stratification of patients after AMI.

The relationship between renal function and outcome from heart valve surgery.

BACKGROUND: The prognostic importance of renal function in patients undergoing surgery for valvular heart disease is poorly defined. The current study addresses this issue. METHODS: Baseline demographic and clinical variables, including the European system for cardiac operative risk evaluation (EuroSCORE), were recorded prospectively from 514 consecutive patients undergoing heart valve surgery between April 2000 and March 2004. Patients with active infective endocarditis and/or requiring emergency surgery were excluded. The glomerular filtration rate was estimated (eGFR) using the Modification of Diet in Renal Disease equation. The primary outcome was all-cause mortality. RESULTS: During a median follow-up of 2 years, 87 patients died. In univariable analysis, both eGFR (hazard ratio [HR] 0.69 per 10 mL/min per 1.73 m2, P<.001) and creatinine (HR 1.04 per 10 micromol/L, P<.001) predicted mortality. Estimated GFR was a stronger predictor and was used in subsequent multivariable models. It remained a powerful independent predictor of death in a multivariable model including all study variables (HR 0.70 per 10 mL/min per 1.73 m2 increase, P<.001) and in a model including EuroSCORE (HR 0.64 per 10 mL/min per 1.73 m2 increase, P<.001). After correction for preoperative EuroSCORE, an eGFR of <60 mL/min per 1.73 m2 was associated with an excess hazard of death of 2.31 (P=.001). CONCLUSION: Renal function, particularly the eGFR, is a powerful predictor of outcome in patients undergoing heart valve surgery. This prognostic utility is independent of other recognized risk factors and the EuroSCORE.