Laronidase replacement therapy improves myocardial function in mucopolysaccharidosis I.

We assessed whether laronidase (recombinant human α-L-iduronidase) replacement therapy could improve left ventricular (LV) myocardial function in a 49-year-old woman with mucopolysaccharidosis I (MPS I) and valvular heart disease. After 6 months of laronidase treatment, the concentration of urinary uron acid decreased by 78.8%. Hepatosplenomegaly improved and LV weight decreased by 19.6%. LV ejection fraction assessed by two-dimensional echocardiogram did not change after laronidase treatment. However, in two-dimensional ultrasound speckle tracking imaging method, LV myocardial longitudinal strain (shortening ratio) increased from -13.2 to -17.4%. LV myocardial radial strain (thickening ratio) increased from 26.6 to 83.4%. LV myocardial torsion increased from +6 to +18°. These indexes of myocardial function were normalized after laronidase treatment. Thus, our findings were a first report that laronidase treatment had a beneficial effect on LV myocardial function in an adult patient with MPS I.

Systolic blood pressure response to exercise as a predictor of mortality in patients with chronic heart failure.

It is well known that peak oxygen consumption and heart rate (HR) recovery after exercise obtained from the cardiopulmonary exercise test are prognostic parameters in patients with chronic heart failure (CHF). However, it is unclear whether exercise-induced parameters obtained from the routine exercise stress test predict mortality in patients with CHF. We studied 136 patients (93 males/43 females) with CHF. All patients underwent symptom-limited exercise stress testing. Exercise parameters included exercise duration, exercise-induced HR and systolic blood pressure (SBP), and metabolic equivalents (METs). During the follow-up period (mean 6.2 years), 34 patients died. Survival rates at the 3rd and 5th years were 90% and 83%, respectively. Body mass index was significantly smaller in the nonsurvival group than in the survival group (P < 0.01). The incidence of patients with New York Heart Association III class was higher in the nonsurvival group than in the survival group (P < 0.05). In univariate analysis, predictors of mortality included peak HR and SBP, increases in HR and SBP during exercise, HR and SBP at the 1st minute after exercise, HR at the 3rd minute after exercise, and METs. The use of beta-adrenergic blocking agents was not associated with prognosis. In Cox hazard model analysis, the increase in SBP (P < 0.002), HR at the 3rd minute after exercise (P < 0.05), and METs (P < 0.05) were independent predictors of mortality. SBP response to exercise, HR recovery after exercise, and METs obtained from the routine exercise test predicted mortality in patients with CHF irrespective of the use of beta-adrenergic blocking agents.

Only two-week smoking cessation improves platelet aggregability and intraplatelet redox imbalance of long-term smokers.

OBJECTIVES: We investigated whether and how soon smoking cessation ameliorates the smoking-induced intracellular oxidative stress and platelet aggregability in long-term smokers. BACKGROUND: Smoking is a major risk factor of atherothrombosis. Smoking cessation reduces cardiac events. However, the underlying mechanisms of the beneficial effects remain to be elucidated. METHODS: Twenty-seven male long-term smokers were divided into two groups. Group A (n = 14) quit smoking for four weeks whereas group B (n = 13) resumed smoking two weeks after quitting. Smoking status was monitored by measurement of urinary cotinine. Using gel-filtered platelets, agonist (adenosine diphosphate and collagen)-induced platelet aggregation, platelet-derived nitric oxide (PDNO), intraplatelet nitrotyrosine production, intraplatelet levels of the reduced form of glutathione (GSH) and its oxidized form (GSSG), and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and urinary 8-iso-prostaglandin F(2alpha) (8-iso-PGF(2alpha)), as markers of systemic oxidative stress, were measured. The baseline measurements were similar between the two groups. RESULTS: Smoking cessation quickly reduced agonist-induced platelet aggregations, intraplatelet nitrotyrosine level, and urinary productions of 8-OHdG and 8-iso-PGF(2alpha) by two weeks in both groups. In group A, they were maintained at the low levels until four weeks, whereas they were reversed by resmoking in group B; PDNO release and intraplatelet GSH/GSSG ratio were time-dependently increased by smoking cessation but reversed by resmoking. CONCLUSIONS: The present findings are the first demonstration that only two weeks of smoking cessation can ameliorate the enhanced platelet aggregability and intraplatelet redox imbalance in long-term smokers, possibly by decreasing oxidative stress. Our findings may strengthen the motivation for smokers to quit smoking.