Stable Disease

Abstract: Objectives To test whether knees which recently developed disease were at higher risk for subsequent x-ray progression than knees which had been stable, suggesting that recent change produces further change and recent stability yields subsequent stability (a pattern of inertia). Methods We used central readings of the annual posteroanterior x-rays obtained in the Osteoarthritis Initiative (OAI) focusing on change in Kellgren and Lawrence (KL) grade and change in semiquantitative joint space. We examined whether knees that had developed incident disease (KL grade 2) were at higher risk of subsequent progression than knees that were already grade 2 and had had stable disease. We combined data from multiple examinations. Using generalised estimating equations to adjust for the correlation between knees, we carried out logistic regression evaluating the risk for disease progression testing incident versus stable disease adjusting for age, sex, body mass index, physical activity, quadriceps strength and mechanical alignment. Results 1562 OAI subjects with grade 2 disease had a mean age of 61.8 years, mean BMI of 29.4, and 61.7% were women. Of knees with stable disease, 4.1% showed progression within the next 12 months in KL grade versus 13.7% in those with incident disease (adjusted OR 4.0; 95% CI 2.4 to 6.7). For progression of joint space loss, we found a similar relation with incident versus stable disease (adjusted OR 5.3; 95% CI 3.6 to 7.9). Conclusions Knee osteoarthritis radiographic progression follows a pattern of inertia. Factors that trigger the transition from stable disease to progression should be sought.

Abstract: • Two hundred fifty-four patients with definite multiple sclerosis were followed up prospectively for 1 to 5 years (mean, 2.6 years). None of the patients received immunosuppressive medication. Yearly exacerbation rates and each patient's adherence to initial disease type were determined. Disease type was defined at entry and prospectively each subsequent year as stable, relapsing remitting stable, relapsing remitting progressive, or chronic progressive. Exacerbation rates determined prospectively did not decline significantly during 3 years of follow-up, even if patients were stratified by disease duration. Adherence to the initially assigned disease type was highly variable. When followed up for 2 years, 30% of patients with chronic progressive disease had conditions become stable, 32% of patients with stable disease had conditions become chronic progressive, 20% of patients with relapsing remitting disease had conditions become stable, and 20% of patients with relapsing remitting disease had conditions become chronic progressive. Patients with stable or relapsing remitting stable disease switched to one of the progressive categories as frequently (44%) as patients with progressive disease stabilized (46%). Progression of disease measured by changes in Kurtzke Expanded Disability Status Scores did not differ between the different disease types. The results challenge dogma regarding the natural history of exacerbation rates and the assumption that we can reliably assign patients to a specific disease type. The findings have important implications for understanding the natural history of multiple sclerosis and designing clinical trials.

Abstract: The devolutionary pattern of coronary atherosclerosis in patients with angina pectoris was studied in 47 persons cinearteriographically. Two subsets of patients were identified at the initial examination. The first comprised 12 patients who did not have coronary atherosclerosis. In these 12, the cinearteriographic findings remained normal on repeated study 15 to 73 months later. The second subset included 35 patients with severe obstructive coronary atherosclerosis. When coronary visualization was repeated 15 months later, arterial disease remained stable in 11 patients (31.4 percent). Significant progression of the arterial disease was observed in the remaining 24 patients (68.5 percent). The frequency of hyperlipidemia, clinical diabetes, systolic and diastolic hypertension and a positive family history of coronary heart disease was not significantly different in those with stable and progressive disease. Furthermore, the distribution of the initial disease did not distinguish one group from the other. Since collateral channels were more prolific in patients who ultimately were classified as having stable arterial disease, it is possible that the initial severity of disease in this group was greater than in those with progressive disease. None in the latter group noted a reduction in the frequency or severity of angina pectoris. One third of those with stable disease did record such a reduction. However, paradoxically, two patients with stable coronary disease had a new myocardial infarction in the interval between examinations. Our findings suggest that the devolutionary pattern of coronary atherosclerosis in patients with angina pectoris as observed cinearteriographicaliy is unpredictable and apparently unrelated to commonly cited risk factors. They indicate that the severity of angina pectoris is the most precise guide to progressive coronary artery disease even though progressive disease can occur without affecting angina. The occurrence of myocardial infarction in patients with stable disease underscores the fact that many determinants influencing myocardial perfusion are not identified by cinearteriography.