Walking distance, improving

Therapeutic results obtained from the administration of a peripheral vasodilating drug may not occur immediately. In some instances, results are minimal. The nurse assesses involved extremities daily for changes in color and temperature and records die patient s comments regarding relief from pain or discomfort. The nurse should monitor die blood pressure and pulse one to two times per day because tiiese dru may cause a decrease in blood pressure The anticipated result of tiierapy for cerebral vascular disease is an improvement in die patient s mental status. When die drug is taken for intermittent claudication, the nurse assesses the patient for increased walking distance without pain. 

Intermittent claudication appears to benefit from ginkgo therapy many studies demonstrate improved walking distance and decreased pain. One meta-analysis of eight studies documented statistically significant improvement but questioned its clinical relevance. In some studies, the high doses (240 mg) appeared more effective. 

Mectianism of Action A phosphodiesterase III inhibitor that inhibits platelet aggregation. Dilates vascular beds with greatest dilation in femoral beds. Therapeutic Effect Improves walking distance in patients with intermittent claudication. Pharmacokinetics Moderately absorbed from the GI tract. Protein binding 95%-98%. Extensively metabolized in the liver. Excreted primarily in the urine and, to a lesser extent, in the feces. Not removed by hemodialysis. Half-life 11-13 hr. Therapeutic effect is usually noted in 2-4 wk but may take as long as 12 wk. 

Beraprost is a stable, orally active analogue of PGI2. It has been tested in patients with intermittent claudication in a randomized, placebo-controlled trial (1). Beraprost improved walking distance more often than placebo. It also reduced the incidence of critical cardiovascular events, but the trial was not powered for statistical validation of this effect. As with iloprost, headache and flushing were the most common adverse effects. 

Clinical investigations of the use of vitamin E in treating vascular disorders associated with hypoxia have been more successful [194]. In intermittent claudication, Boyd, Ratcliffe, Jepson and James [195] reported a 78% improvement over a 6 month trial period, while Haeger [ 196, 197] observed significant increases in walking distance in patients with intermittent claudication receiving 300 mg a-tocopherol acetate per day for 2-5 years. This condition currently represents the most potentially useful clinical area for administration of the vitamin in pharmacological doses. 

Mechanism of action that provides symptom relief with pentoxifylline is poorly understood but is thought to involve red blood cell deformability as well as a reduction in fibrinogen concentration, platelet adhesiveness and whole blood viscosity (75). The recommended dose of pentoxifylline is 400 mg three times daily with meals. Pentoxifylline causes a marginal but statistically significant improvement in pain-free and maximal walking distance (a net benefit of 44 m in the maximal distance walked on a treadmill (95% Cl, 0 14 to 0 74) based on meta-analyses of randomized, placebo-controlled, double-blind clinical trials (76). At the same time pentoxifylline does not increase the ABI at rest or after exercise (56). Pentoxifylline may be used to treat patients with intermittent claudication however, it is likely to be of marginal clinical importance (56,77). Medical therapies... 

After 180 days of treatment there was a significant improvement of 73 9% (mean SE) in maximal walking distance in PAD patients treated with propionyl-L-carnitine compared to placebo (80). Propionyl-L-camitine has been shown to improve treadmill performance and quality of life in patients with claudication. After six months of treatment, subjects randomly assigned to propionyl-L-carnitine increased their peak walking time by 162 222 seconds (a 54% increase) as compared with an improvement of 75 191 seconds (a 25% increase) for those on placebo (p < 0.001) (81). 

A US study, however, showed that administration of beraprost did not improve the pain-free walking distance or the quality-of-life measures between the treatment groups (85). 

Mohler ER111, Hiatt WR, Creager MA. Cholesterol reduction with atorvastatin improves walking distance in patients with peripheral arterial disease. Circulation 2003 108(12) 1481-1486. 

Six multicenter placebo-controUed trials have been conducted in the USA (3,4). They involved more than 2000 patients with intermittent claudication and established the efficacy of cilostazol in improving walking distance in these patients. 

Violi F, Marubini E, Coccheri S, Nenci GG. Improvement of walking distance by defibrotide in patients with intermittent claudication—results of a randomized, placebo-controUed study (the DICLIS study). Defibrotide Intermittent CLaudication Italian Study. Thromb Haemost 2000 83(5) 672-7. 

In another study, 800 mg of dried garlic powder (Kwai/Sapec) daily for 15 weeks significantly improved pain-free walking distance in patients with... 

In such trials as MUSTIC (7), PATH-CHF (8), MIRACLE (9), CONTAK CD (10), MIRACLE ICD (11), and PATH-CHF II (12), resynchronization therapy consistently improved functional capacity and reduced symptoms. Specifically, resynchronization was associated with a 1% to 23% improvement in 6-minute hall walk distance, a 7% to 10% increase in V02max, and an 11% to 31% improvement in quality of life scores. 

MUSTIC, PATH-CHF, MIRACLE, CONTAK CD, MIRACLE ICD, and PATH-CHF II enrolled patients with (a) moderate to severely symptomatic (NYHA class III—IV) CHF despite optimal medical therapy (b) severe left ventricular systolic dysfunction (LVEF <35%) (c) a wide QRS complex (generally defined as a QRS >120-130 msec) and (d) sinus rhythm. As a result, these inclusion criteria have become the standard indications for CRT. The effects in these conventional indication trials are robust—indeed, far more robust than the effects observed with conventional pharmacologic therapy of heart failure (Figure 5.1). For instance, improvement in 6-minute hall walk distance was observed in only 2 of 6 trials of ACE-inhibitors, 3 of 17 trials of beta blockers, and 1 of 4 trials of digoxin (13). Trials of both beta-blockers and ACE inhibitors have likewise shown inconsistent results with respect to V02max (14,15) and quality of life (16,17). 

While the true impact of rhythm control on mortality remains to be determined, current data suggest that the restoration and maintenance of sinus rhythm in patients with AF may impart other important clinical benefits, such as improvements in symptoms, exercise tolerance, ability to perform activities of daily living and quality of life (41). In the Rate Control versus Electrical Cardioversion (RACE) study, patients with AF who converted to sinus rhythm had a significant reduction in atrial size and improvement in left ventricular function (36). Despite efforts to enroll patients who would tolerate rate-controlled AF, the AFFIRM Functional Status Substudy showed that AF was associated with poorer New York Heart Association (NYHA) functional capacity and rhythm control was associated with a modest improvement in six-minute walk distance compared to rate control (42). 

---