Focused cardiac ultrasonography (FoCUS) used to assist clinical evaluation greatly improves diagnostic sensitivity (but not specificity) for cardiovascular disease and should be performed as an extension of the physical examination, according to a study published in the Annals of Internal Medicine.
The investigators of this study sought to compare the accuracy of FoCUS-assisted clinical assessment vs clinical assessment alone for diagnosing left ventricular dysfunction or valvular disease in adults undergoing bedside cardiovascular evaluation.
The investigators searched MEDLINE, Embase, and Web of Science databases to identify prospective and retrospective studies published from January 1990 to May 2019, comparing the diagnostic accuracy of cardiovascular evaluation via FoCUS-assisted clinical assessment to clinical assessment alone. Studies included adults undergoing bedside clinical examination for the diagnosis of left ventricular dysfunction, aortic or mitral valve disease, or pericardial effusion. All studies used transthoracic echocardiography as a reference standard. The investigators performed a meta-analysis on a total of 9 relevant studies, which included 1189 patients with a median sample size of 84 participants and a median of mean patient age of 64 years.
Compared with clinical assessment alone, the sensitivity of FoCUS-assisted assessment for diagnosing left ventricular dysfunction (defined as left ventricular ejection fraction <50%) was significantly greater (84% [95% CI, 74%-91%] vs 43% [95% CI, 33%-54%], respectively). However, the specificity of FoCUS-assisted assessment vs clinical assessment alone was similar (89% [95% CI, 85%-91%] vs 81% [95% CI, 65%-90%], respectively).
For diagnosing moderately severe aortic or mitral valve disease, the sensitivities of FoCUS-assisted examination and clinical assessment alone were 71% (95% CI, 63%-79%) and 46% (95% CI, 35%-58%), respectively; the specificity of each approach was the same at 94% (95% CI, 91%-96%). Only one study reported data on the accuracy of examination modalities for pericardial effusion in which FoCUS-assisted assessment had a sensitivity of 98% and a specificity of 95%, and clinical assessment alone had a sensitivity of 48% and a specificity of 62%.
Limitations to the study included varied clinical settings and level of clinical expertise and ultrasonography experience, inadequate evidence on pericardial effusion, and using a comparative design. Finally, most researchers of the study included in the meta-analysis reported either unclear or high risk for bias.
FoCUS-assisted examination was more sensitive for detecting left ventricular dysfunction and valve diseases compared with clinical assessment alone; however, both modalities were similar in specificity. Researchers of the study concluded that clinical examination assisted by FoCUS can rule out certain cardiovascular pathology but may not be sufficient to confirm cardiovascular disease. FoCUS should not replace formal echocardiography but rather be performed as an extension of the physical examination.
Marbach JA, Almufleh A, Di Santo P, et al. Comparative accuracy of focused cardiac ultrasonography and clinical examination for left ventricular dysfunction and valvular heart disease: A systematic review and meta-analysis [published online August 6, 2019]. Ann Intern Med. doi:10.7326/M19-1337