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Articles by S Frantz
Total Records ( 2 ) for S Frantz
  N Burkard , T Williams , M Czolbe , N Blomer , F Panther , M Link , D Fraccarollo , J. D Widder , K Hu , H Han , U Hofmann , S Frantz , P Nordbeck , J Bulla , K Schuh and O. Ritter
  Background—

We previously demonstrated that conditional overexpression of neuronal nitric oxide synthase (nNOS) inhibited L-type Ca2+ channels and decreased myocardial contractility. However, nNOS has multiple targets within the cardiac myocyte. We now hypothesize that nNOS overexpression is cardioprotective after ischemia/reperfusion because of inhibition of mitochondrial function and a reduction in reactive oxygen species generation.

Methods and Results—

Ischemia/reperfusion injury in wild-type mice resulted in nNOS accumulation in the mitochondria. Similarly, transgenic nNOS overexpression caused nNOS abundance in mitochondria. nNOS translocation into the mitochondria was dependent on heat shock protein 90. Ischemia/reperfusion experiments in isolated hearts showed a cardioprotective effect of nNOS overexpression. Infarct size in vivo was also significantly reduced. nNOS overexpression also caused a significant increase in mitochondrial nitrite levels accompanied by a decrease of cytochrome c oxidase activity. Accordingly, O2 consumption in isolated heart muscle strips was decreased in nNOS-overexpressing nNOS+/MHC-tTA+ mice already under resting conditions. Additionally, we found that the reactive oxygen species concentration was significantly decreased in hearts of nNOS-overexpressing nNOS+/MHC-tTA+ mice compared with noninduced nNOS+/MHC-tTA+ animals.

Conclusion—

We demonstrated that conditional transgenic overexpression of nNOS resulted in myocardial protection after ischemia/reperfusion injury. Besides a reduction in reactive oxygen species generation, this might be caused by nitrite-mediated inhibition of mitochondrial function, which reduced myocardial oxygen consumption already under baseline conditions.

  G Guder , S Frantz , J Bauersachs , B Allolio , C Wanner , M. T Koller , G Ertl , C. E Angermann and S. Stork
 

Background— Observational studies indicate that classical cardiovascular risk factors as body mass index, total cholesterol, and systolic blood pressure are associated with improved rather than impaired survival in heart failure ("reverse epidemiology"). We estimated the prognostic role of these risk factors in unselected patients with heart failure.

Methods and Results— Consecutive subjects with heart failure of any cause and severity were enrolled (n=867), and survivors were followed for a median period of 594 days (25th to 75th percentile, 435 to 840). Mean age was 70±13 years, 41% were female, New York Heart Association class distribution I through IV was 15%/29%/41%/15%, and 49% had preserved left ventricular ejection function. At follow-up, 34% of the patients had died. Low levels of any risk factor (ie, body mass index, total cholesterol, and systolic blood pressure in the low tertile) indicated the highest mortality risk. After adjustment for age, sex, New York Heart Association class, and ejection fraction, ≥2 risk factors in the high tertile indicated a relative reduction in mortality risk of 51% (hazard ratio, 0.49; 95% CI, 0.35 to 0.68; P=0.001) compared with subjects with 3 risk factors in the low tertile. Further adjustment for cause of heart failure, relevant comorbidities, medication, and biomarkers attenuated this association only modestly (hazard ratio, 0.63; 95% CI, 0.45 to 0.89; P=0.009).

Conclusion— In patients with heart failure, mortality risk counterintuitively increased on a cumulative scale with lower levels of body mass index, total cholesterol, and systolic blood pressure, irrespective of the type and severity of heart failure. Future studies need to identify whether risk factor control as presently recommended should be advocated in all patients with heart failure.

 
 
 
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