Measurement of Endothelial Function and Cardiac Output: New Methods

Inclusion Criteria: * Clinically stable for the last 4 weeks (not for HFrEF: 7 days) * Signed consent form HFpEF: * Baseline-Echocardiography: * hospitalization \<= 12 months with diagnosis heart failure and E/E' \> 8 or E' \< 8 cm/s or * BNP \>= 100pg/ml or NT-proBNP \>= 300pg/ml in the last 6 months or * LAVI \> 28 ml/m² and E/E' \> 8 or E' \< 8cm/s or PAPsys \> 40mmHg and E/E' \> 8 or E' \< 8 cm/s * Possibility to take part in cardiac stress test * Heart failure NYHA I-III * Sinus rhythm * Max. O2-uptake on exertion \< 20ml/kgBW/min HFrEF * HFrEF due to ischemic or non-ischemic reasons * NYHA I-III * Individually optimized and stable pharmacological therapy (including beta-blocker, ACE-Inhibitor, AT1-antagonist, aldosterone-antagonist) * EF \<=45%, Simpson Biplan PH * NICE-Classification 2013 I/II * PAH \>= 25 mmHg * Precapillary PAH: Wedge-pressure \<= 15 mmHg, CO normal or low * Postcapillary PAH: Wedge-pressure \>= 15 mmHg, CO normal or low Diabetic nephropathy: * Diabetes mellitus Type 2 with oral or Insulin therapy and one or more of the following: * Diabetic nephropathy has been diagnosed before (anamnesis) * Macroalbuminuria: Urine Albumine/Creatinine-ratio \> 300mg/g Creatinine (\>34mg/mmol) in 2 out of 3 tests of Urine in the morning and GFR \<90ml/min/1.73m² (CKD-EPI) * Microalbuminuria: 30-300mg/g Creatinine (\>=3.4 mg/mmol but \<34mg/mmol) tested as above and GFR \< 90 ml/min/1.73m² and diabetic retinopathy AH: * Hypertension diagnosed at least 6 months except structural heart disease: EF \> 55% and no sign of HFpEF * No symptoms of coronary heart disease * Possibility to take part in cardiac stress test * Stable pharmacologic therapy of Hypertension for at least 4 weeks * Systolic blood pressure \<140 mmHG during Screening Exclusion Criteria: * Patient incapable of contracting * Angina pectoris \> CCS II * Coronary Intervention in the last 4 weeks or scheduled Intervention/Bypass * Myocardial infarction in the last 3 months * Stroke in the last 3 months * Valvular heart disease \> II° * Cardiomyopathy due to Infiltrate/hypertrophic obstruction (e.g. HOCM, Amyloidosis) * Congenital complex heart disease * Active myocarditis * Significant lung disease * Significant Cardiac dysrhythmia * Scheduled changes in medication during time of study * (Scheduled) heart transplant * Cardiac resynchronisation therapy over the last three months * ICD/Pacemaker-implant in the last 4 weeks * Uncontrolled Hyper/Hypotension (\>180mmHg, \<95mmHg) * Patient taking part in Rehabilitation program * Diagnosed Malignant disease or disease with life expectancy \< 1 year * Anemia with Hb\<10mg/dl * Untreated significant thyroid disease HFpEF, Hypertension and PH: * Patient incapable of cardiac stress test (e.g. because of orthopedic Problems) * Significant changes in cardiovascular Status over the two weeks of study * Instable cardiopulmonary Status over the last four weeks HFrEF: * I.v. Treatment with inotropic drug or diuretic in the last 7 days before Screening * Myocardial infarction in the last 4 weeks