Association Between Transthoracic Echocardiography Appropriateness and Echocardiographic Findings

BACKGROUND

The association between appropriate use criteria and echocardiographic findings in patients with chronic cardiovascular diseases is unknown.

METHODS

As a substudy of the Echo WISELY (Will Inappropriate Scenarios for Echocardiography Lessen Significantly) trial, 9,230 transthoracic echocardiographic (TTE) examinations from six Ontario academic hospitals were linked to a registry of echocardiographic findings. The TTE studies were rated appropriate), rarely appropriate, or may be appropriate according to the 2011 appropriate use criteria. TTE findings of appropriately ordered examinations were compared with those of rarely appropriate examinations for specific disease subsets, including heart failure and valvular heart disease.

RESULTS

There were 7,574, 1,087, and 569 TTE examinations ordered for appropriate, rarely appropriate, and may be appropriate indications, and of the 7,574 appropriate studies, 6,399 were ordered for specific indications and 1,175 for general indications. TTE examinations ordered for general indications had lower rates of left ventricular dysfunction (19.6% vs 9.1%, P < .001) and moderate to severe aortic stenosis (15.5% vs 2.6%, P < .001). Of the 2,395 TTE examinations ordered for patients with heart failure, appropriately ordered studies were more likely to result in left ventricular segmental abnormality (37.0% vs 24.9%, P = .012) but similar rates of right ventricular dilatation (15.4% vs 14.7%, P = .79), right ventricular dysfunction (14.8% vs 11.3%, P = .22), and moderate to severe mitral regurgitation (12.1% vs 9.2%, P = .35). Of the 2,859 studies ordered to assess valvular heart disease, appropriately ordered studies were significantly more likely to find moderate to severe valvular pathology, including aortic stenosis (30.4% vs 24.6%, P = .008), aortic regurgitation (8.9% vs 1.6%, P < .001), mitral stenosis (6.7% vs 3.1%, P = .002), and mitral regurgitation (16.1% vs 6.1%, P < .001), but similar rates of tricuspid regurgitation (11.2% vs 13.0%, P = .60).

CONCLUSIONS

Overall, appropriately ordered TTE examinations for heart failure and valvular heart disease were significantly more likely to have abnormal findings than rarely appropriate examinations. TTE studies ordered for general indications had fewer, although still a significant proportion, of abnormalities compared with studies ordered for specific indications.

Primary prevention of cardiovascular disease: global cardiovascular risk assessment and management in clinical practice

Aims

For the primary prevention of cardiovascular disease, the Framingham Risk Score (FRS) is the most well-known risk prediction method. However, there are limited data regarding physicians' method of risk assessment and guideline adherence in clinical practice.

Methods and results

In the PARADIGM (Primary cARe AuDIt of Global risk Management) study (March 2009-10), 105 primary care physicians across Canada prospectively collected data for 3015 patients (mean age 56 years, 59% men) without known cardiovascular disease, diabetes, or lipid-lowering medications at baseline. For each patient, the treating physician determined their cardiovascular risk, and reported the risk stratification method and subsequent treatment decisions. Kappa statistics assessed the agreement between the study-calculated FRS and the treating physician's reported risk assessment. The FRS was the most commonly reported risk assessment method, but was used in only 34.0% of patients. Regardless of the method used (even if the FRS was reportedly used), there was only fair agreement between the risk stratification as reported by the physician and the study-calculated FRS. Moreover, physicians recommended statin initiation in 92% of all patients that they identified as high risk; however, according to the study-calculated FRS, only 56% of the truly high-risk patients were recommended statin therapy.

Conclusion

For the primary prevention of cardiovascular disease, these findings indicate a need to improve risk assessment and stratification, as misclassification directly contributes to suboptimal risk factor management in real-world clinical practice. Future studies should establish the optimal risk stratification method with quality improvement strategies for its subsequent implementation.

Clinical Trial Registration

http://clinicaltrials.gov/ct2/show/NCT00950703; NCT00950703.

The nature of the oil phase and the release of solutes from multiple (w/o/w) emulsions

The effect of the nature of the oil phase of w/o/w emulsions stabilized by interfacial complexation between span 80 (sorbitan mono-oleate) and albumin has been studied. The long-term stability of the systems has been assessed by photomicrography and by measuring the quantity of an internal marker (NaCl) remaining entrapped with time. The number of multiple oil drops and the diameters of the internal aqueous droplets were determined over 6 weeks, and the amounts of NaCl entrapped over the same period were followed. There were no significant changes in w/o/w emulsions prepared with a range of hydrocarbons (octane, dodecane, hexadecane, toluene and cyclohexane), indicating stable multiple emulsions. The release of NaCl and 5-fluorouracil (5-FU) separately entrapped in the internal aqueous phase of w/o/w emulsions was measured. Diffusion of the un-ionized species of 5-FU across the oil phase or through localized thin oil lamellae is the primary transport mechanism. In the presence of surface active agents, water is solubilized in inverse micelles which would possess the ability to solubilize other water-soluble components, such as NaCl and 5-FU. The mixed inverse micellar units of Span 80 and polysorbate (Tween) 80 therefore act as solute carriers across the liquid hydrocarbon membrane separating the two aqueous phases of the emulsions. The main factor in determining the differences in rates of release from the hydrocarbon emulsions appears to be the droplet size of the internal aqueous phase.