Comparative Assessment of Mitral Regurgitation Severity by Transthoracic Echocardiography and Cardiac Magnetic Resonance Using an Integrative and Quantitative Approach.

Although transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) are validated in quantitation of mitral regurgitation (MR), discrepancies may occur. This study assesses the agreement between TTE and CMR in MR and evaluates characteristics and clinical outcome of patients with discrepancy. From our institutional database, 70 subjects with MR underwent both TTE and CMR within 30 days (median 3 days). MR was evaluated semiquantitatively (n = 70) using a 4-grade scale and quantitatively (n = 60) with calculation of regurgitant volume (RVol) and regurgitant fraction (RF). Of the 70 subjects, qualitative assessment by TTE yielded 30 subjects with mild MR, 17 moderate, and 23 moderately severe or severe MR. Exact concordance in MR grade was seen in 50% and increased to 91% when considering concordance within one grade of severity (κ = 0.44). A modest correlation was observed for RVol and RF between both methods (r = 0.59 and 0.54, respectively, p <0.0001). Ten patients had a significant discrepancy in quantitative MR (difference in RF >20%); the frequency of secondary MR was higher (100% vs 46%; p = 0.003) in patients with discrepancy. Although interobserver variability in RF was higher with TTE compared with CMR (-5.5 ± 15% vs 0.1 ± 7.3%), patients with discrepancy were equally distributed by severity and clinical outcome without an overestimation by either method. In conclusion, there is a modest agreement between TTE and CMR in assessing MR severity. In patients with discrepancy, there is a higher prevalence of functional MR, without a consistent overestimation of MR severity by either method.

The diastolic stress test: a new approach to an old problem.

The evaluation of ischemic heart disease is the cornerstone of clinical Cardiology. Although there are many means of ischemic evaluation, all are with their own limitations. While perfusion-based studies are highly sensitive, they lack specificity. Conversely, systolic wall motion analysis with echocardiography tends to have high specificity; however, the sensitivity may be limited by short duration of systolic abnormalities when present. With the advent of Doppler echocardiography, and more specifically tissue Doppler imaging, and strain and strain rate imaging, a more comprehensive evaluation of the left ventricular function is available, including diastole. Diastolic abnormalities in the setting of ischemia are now being studied using these new parameters and have been suggested as a reliable marker of ischemia. Exercise-induced abnormalities in diastolic parameters have improved sensitivities and specificities over traditional stress testing and persist longer than systolic abnormalities. A review of the medical literature regarding the subject will be discussed here.

Meta-analysis of adverse cardiovascular events associated with echocardiographic contrast agents.

In October 2007, the Federal Drug Agency issued a black box warning for contrast agents used in patients undergoing echocardiography and restricted their use in patients with acute coronary syndrome, a decompensated heart, and respiratory failure. We performed a systemic review and meta-analysis to study the adverse effects of contrast agents used with respect to myocardial infarction and all-cause mortality. MEDLINE, EMBASE, BIOSIS, and Cochrane databases from inception to October 2009 were searched for studies that reported myocardial infarction and all-cause mortality after the use of contrast agents for echocardiography. A total of 8 studies were included in the present meta-analysis. A random-effect model was used, and between-studies heterogeneity was estimated with I(2). A total of 8 studies reported death as an outcome and only 4 reported myocardial infarction. The incidence of death in the contrast group was 0.34% (726 of 211,162 patients) compared to 0.9% (45,970 of 5,078,666 patients) in the noncontrast group. The pooled odds ratio was 0.57 (95% confidence interval 0.32 to 1.01, p = 0.05). The reported incidence of myocardial infarction in the contrast group was 0.15% (86 of 57,264 patients) compared to 0.2% (92 of 44,503 patients) in the noncontrast group. The pooled odds ratio was 0.85 (95% confidence interval 0.35 to 2.05, p = 0.72). Significant heterogeneity was seen among the studies. In conclusion, the cumulative evidence has suggested that the use of contrast agents for echocardiography is safe and not associated with a greater incidence of myocardial infarction or and mortality.

Impact of contrast echocardiography on evaluation of ventricular function and clinical management in a large prospective cohort.

OBJECTIVES: The aim of this study was to evaluate the impact of echocardiographic contrast utilization on patient diagnosis and management. BACKGROUND: Contrast echocardiography (CE) has improved visualization of endocardial borders. However, its impact on patient management has not been evaluated previously. METHODS: We prospectively enrolled 632 consecutive patients with technically difficult echocardiographic studies who received intravenous contrast (Definity, Lantheus Medical Imaging, Billerica, Massachusetts). Quality of studies, number of left ventricular (LV) segments visualized, estimated ejection fraction, presence of apical thrombus, and management decisions were compared before and after contrast. RESULTS: After CE, the percent of uninterpretable studies decreased from 11.7% to 0.3% and technically difficult studies decreased from 86.7% to 9.8% (p < 0.0001). Before contrast, 11.6 +/- 3.3 of 17 LV segments were seen, which improved after CE to 16.8 +/- 1.1 (p < 0.0001). An LV thrombus was suspected in 35 patients and was definite in 3 patients before CE. After contrast, only 1 patient had a suspected thrombus, and 5 additional patients with thrombus were identified (p < 0.0001). A significant impact of CE on management was observed: additional diagnostic procedures were avoided in 32.8% of patients and drug management was altered in 10.4%, with a total impact (procedures avoided, change in drugs, or both) observed in 35.6% of patients. The impact of contrast increased with worsening quality of nonenhanced study, the highest being in intensive care units. A cost-benefit analysis showed a significant savings using contrast ($122/patient). CONCLUSIONS: The utilization of CE in technically difficult cases improves endocardial visualization and impacts cardiac diagnosis, resource utilization, and patient management.