A new clinical model in pulmonary embolism and its correlation with V/P scan results

The study was prospectively designed to assess the correlation between a new clinical model empirically developed for acute pulmonary embolism (PE) and ventilation/perfusion (V/P) scan results. One hundred sixty consecutive patients with suspected acute PE underwent clinical evaluation before V/P scintigraphy. The clinical probability of PE was categorized according to a structured clinical model empirically developed as low, intermediate, or high, and the results were compared with those of V/P scintigraphy. Forty, 61, and 59 patients were classified as low, intermediate, and high clinical probability, respectively. Seventy-five percent (30/40) of the patients with low clinical probability were also of low scintigraphic probability or had a normal result (r(s): 0.39, p=0.000); 28% (17/61) of the patients with intermediate clinical probability demonstrated intermediate scintigraphic probability (r(s): 0.20, p=0.012); and 68% (40/59) of the patients with high clinical probability were also of high scintigraphic probability (r(s): 0.43, p=0.000). Overall, the correlation of two scoring systems was statistically significant (r(s): 0.39, p=0.000). Unilateral leg swelling (p=0.027), syncope or near syncope (p=0.002), amputation of a hilar artery (p=0.007), and electrocardiographic signs of right ventricular overload (p=0.000) prevailed in patients with high scintigraphic probability. "Syncope-near syncope or hemodynamic collapse" PLUS "electrocardiographic signs of right ventricular overload or hypoxemia" combination had the most significant correlation with a high scintigraphic probability (r(s): 0.31; p=0.000). In conclusion, the new clinical model empirically developed was significantly successful to provide comparable results with V/P scan. This consistency was particularly prominent in patients with low or high clinical probability for PE.