Interims Analysis of a Prospective Observational Study on the Use of Cilostazol (Pletal®) in Daily Clinical Vascularsurgical Practice

Background and Aims: Peripheral arterial occlusion disease (PAOD) has undergone a systematic classification of findings and stage-adapted sequential therapy. After the former limited otions of a conservative, rather medication-based approach, Cilostazol has led to more flexibility in the non-interventional therapeutic profile in angiologically clearly defined indications. The aim of this first interims analysis was to evaluate the preliminary results of the prospective observational study on the effect of Cilostazol (Pletal (R), 2 x 100 mg; UCB Pharma Deutschland GmbH, Monheim, Germany - primary/secondary end points: increase of walking distance/quality of life including side effects) used according to its appropriate indication in daily clinical practice (effectiveness), which were obtained in a representative group of exclusively vascular surgical patients in a centre for vascular medicine. Patients and Methods: Through a defined study period, all consecutive patients were enrolled in whom a Cilostazol medication was initiated after official approval of the pharmakon in the Division of Vascular Surgery or outpatient clinic because of PAOD, stage II b, indicated by a subjective walking distance of <200 m with a minimal observational study period of 6 months, a 12-week study-appointment interval (as recommended to each) and a reliable compliance with regard to patient data and medication. Primary study end point was the absolute increase of pain-free walking distance (as measured on the treadmill under standardised conditions, statistically tested by ANOVA for repeated measurements as well as pairwise t tests); secondary end point was the change of quality of life (determined semiquantitatively by the requested assessments "worse - equal - better"). In addition, the side effect profile and the spectrum of accompanying diseases with its possible alterations of impact on the Cilostazol effect were registered. Results: Over 1.5 years, 40 patients were documented (male/female = 23 : 17 [67.5/32.5%]) with a mean age of 65.7 +/- 9.1 (range: 41-88; median: 47.1) years. In the spectrum of accompanying diseases (registration rate, 95%; n=38), arterial hypertension (n=25; 62%), hyperlipoproteinaemia (58%; n=23), diabetes (28%; n=11), obesity (25%; n=10) and nicotine misuse (23%; n=9) predominated. On average, treatments lasted 235 (range: 3-566) days. Overall, there was a continuous prolongation of the walking distance up to 12 months after initiation of Cilostazol. The objective walking distance (treadmill) was 250 m at time "0", after 3 and 6 months + 114 m (P=0.009) and + 157 m (P=0.001), respectively - all statistics are based on completely documented data of the single study patients over the observational time period). Quality of life reached a statistically detectable improvement after 6 months. In smokers, there was no detectable significant increase of walking distance under Cilostazol. In 11/38 individuals (registration rate, 95%), side effects were reported: Hyperglycaemia and tachycardia was found in 2 cases (5.3% each); diarrhoea, anxiousness, headache, changing blood pressure, jaundice, nausea, n=1. The AB index was not a feasible parameter (not shown). Discussion: Use of Cilostazol in daily clinical practice is safe, effective and causes an early increase of the walking distance (after 3 months) and, but delayed, an improvement of the quality of life also in vascular surgical patients. Conclusion: Cilostazol medication can be considered a suitable tool as: (i)an initial step in the sequential therapeutic algorithm in stage II b of PAOD, (ii)a therapeutic alternative in exhausted vascular surgical (interventional) options. Further study-based clinical observations on the use of Cilostazol appear to be indicated.