A COMPARISON OF OUTCOME CRITERIA IN THE DIAGNOSIS OF RENOVASCULAR HYPERTENSION

The outcome criteria used for the diagnosis of renovascular hypertensi on (RVHT) following renal revascularization have not been validated. D iffering criteria of indeterminate accuracy have yielded conflicting c onclusions concerning the prevalence and efficacy of treatment of RVHT . We compared the accuracy of conventional outcome criteria used in th e diagnosis of RVHT to that of a novel, ordered outcome analysis to de termine whether such an analysis might provide a more consistent means of diagnosing RVHT. Twenty-seven patients underwent intervention for treatment of presumed RVHT (group I), and 40 patients with presumed es sential hypertension were treated with antihypertensive medication alo ne (group II). A standard dichotomized (improved or unimproved) outcom e scheme and a five-level, ordered outcome scheme (ranging from defini tely unimproved to definitely improved) were used to generate nominal outcomes of therapy for each patient. The resultant outcome groups wer e examined to determine the effect of such partitioning on blood press ure and medication requirements. To determine their diagnostic accurac y, the conventional and ordered outcome schemes were compared with a c onsensus outcome scheme derived from the use of numerous criteria. Sig nificant correlations were observed between the ordered outcome score and posttreatment reductions in systolic blood pressure (r = 0.53, p = 0.007), diastolic blood pressure (r = 0.74, p = 0.0001), and medicati on score (r = 0.71, p = 0.0001). Overall diagnostic accuracy was estim ated to be 91% for ordered criteria and 85% for dichotomized criteria. Correlation of the ordered and conventional schemes' assignments with the consensus scheme's assignments was 0.79 (p = 0.0001) and 0.63 (p = 0.0001), respectively. A simple, ordered outcome scheme compares fav orably with the standard dichotomized scheme in assigning a diagnosis of RVHT to patients following renal revascularization or nephrectomy. The ordered scheme offers the advantages of simplicity and accuracy ov er current schemes.