| E.1 Medical condition or disease under investigation | 
| E.1.1 | Medical condition(s) being investigated |  | 
| E.1.1.1 | Medical condition in easily understood language | 
| Heart failure is a condition where the heart does not have enough strength to pump blood all the way round the body efficiently, and causes edema, shortness of breath and reduced physical capacity. |  | 
| E.1.1.2 | Therapeutic area | Diseases [C] - Cardiovascular Diseases [C14] | 
| MedDRA Classification | 
| E.1.2 Medical condition or disease under investigation | 
| 
| E.1.2 | Version | 19.0 |  
| E.1.2 | Level | LLT |  
| E.1.2 | Classification code | 10000803 |  
| E.1.2 | Term | Acute heart failure |  
| E.1.2 | System Organ Class | 100000004849 |  | 
| E.1.2 Medical condition or disease under investigation | 
| 
| E.1.2 | Version | 19.0 |  
| E.1.2 | Level | LLT |  
| E.1.2 | Classification code | 10008908 |  
| E.1.2 | Term | Chronic heart failure |  
| E.1.2 | System Organ Class | 100000004849 |  | 
| E.1.3 | Condition being studied is a rare disease | No | 
| E.2 Objective of the trial | 
| E.2.1 | Main objective of the trial | 
| To compare the pharmacokinetics of metformin in type 2 diabetic patients with heart failure in acute and chronic state. To investigate the influence of polymorphisms in genes encoding the metformin transporter proteins on metformin trough levels in type 2 diabetic heart failure patients.
 |  | 
| E.2.2 | Secondary objectives of the trial |  | 
| E.2.3 | Trial contains a sub-study | Yes | 
| E.2.3.1 | Full title, date and version of each sub-study and their related objectives | 
| Substudy A: To compare the pharmacokinetics of metformin in type 2 diabetic patients with heart failure in acute and chronic state. 
 Substudy B: To investigate the influence of polymorphisms in genes encoding the metformin transporter proteins on metformin trough levels in type 2 diabetic heart failure patients.
 |  | 
| E.3 | Principal inclusion criteria | 
| Substudy A: •	Patients with decompensated heart failure
 •	Increased need for diuretics as judged by the clinicians
 •	LVEF < 45% measured during admission or within 12 months prior to inclusion
 •	NYHA-class I, II, III or IV
 •	Ability to understand the written patient information and to give informed consent
 •	Diabetes Type 2 (and in metformin treatment for > 1 month)
 •	Stable dosage of metformin treatment for at least 1 week prior to examination
 
 Substudy B:
 •	Patients with heart failure
 •	LVEF < 45% within 12 months prior to inclusion
 •	NYHA-class I, II, III or IV
 •	Ability to understand the written patient information and to give informed consent
 •	Diabetes Type 2 (and in metformin treatment for > 1 month)
 •	Stable dosage of metformin treatment for at least 1 week prior to examination
 |  | 
| E.4 | Principal exclusion criteria | 
| Substudy A: •	Severe cardiac failure, defined as
 o	systolic blood pressure continuously < 85 mmHg
 o	signs of tissue hypoperfusion (oliguria < 30 mL/h, altered level of consciousness, rapid deterioration of kidney function)
 o	Need for intravenous inotropic support
 •	Age < 18 years
 •	Current abuse of alcohol or drugs
 •	Adjustment or discontinuation of metformin dose during admission before examination
 
 Substudy B:
 •	Age < 18 years
 •	Current abuse of alcohol or drugs
 |  | 
| E.5 End points | 
| E.5.1 | Primary end point(s) | 
| Substudy A: Changes in renal clearance of metformin between patients with acute and chronic heart failure.
 
 Substudy B:
 Mean trough steady-state concentrations (Css,min) of metformin with emphasis on the intra-interindividual variability in heart failure patients.
 |  | 
| E.5.1.1 | Timepoint(s) of evaluation of this end point |  | 
| E.5.2 | Secondary end point(s) |  | 
| E.5.2.1 | Timepoint(s) of evaluation of this end point |  | 
| E.6 and E.7 Scope of the trial | 
| E.6 | Scope of the trial | 
| E.6.1 | Diagnosis | No | 
| E.6.2 | Prophylaxis | No | 
| E.6.3 | Therapy | No | 
| E.6.4 | Safety | No | 
| E.6.5 | Efficacy | No | 
| E.6.6 | Pharmacokinetic | Yes | 
| E.6.7 | Pharmacodynamic | No | 
| E.6.8 | Bioequivalence | No | 
| E.6.9 | Dose response | No | 
| E.6.10 | Pharmacogenetic | Yes | 
| E.6.11 | Pharmacogenomic | Yes | 
| E.6.12 | Pharmacoeconomic | No | 
| E.6.13 | Others | No | 
| E.7 | Trial type and phase | 
| E.7.1 | Human pharmacology (Phase I) | No | 
| E.7.1.1 | First administration to humans | No | 
| E.7.1.2 | Bioequivalence study | No | 
| E.7.1.3 | Other | No | 
| E.7.1.3.1 | Other trial type description |  | 
| E.7.2 | Therapeutic exploratory (Phase II) | No | 
| E.7.3 | Therapeutic confirmatory (Phase III) | No | 
| E.7.4 | Therapeutic use (Phase IV) | Yes | 
| E.8 Design of the trial | 
| E.8.1 | Controlled | No | 
| E.8.1.1 | Randomised | No | 
| E.8.1.2 | Open | Yes | 
| E.8.1.3 | Single blind | No | 
| E.8.1.4 | Double blind | No | 
| E.8.1.5 | Parallel group | No | 
| E.8.1.6 | Cross over | No | 
| E.8.1.7 | Other | No | 
| E.8.2 | Comparator of controlled trial | 
| E.8.2.1 | Other medicinal product(s) | No | 
| E.8.2.2 | Placebo | No | 
| E.8.2.3 | Other | No | 
| E.8.3 | The trial involves single site in the Member State concerned | Yes | 
| E.8.4 | The trial involves multiple sites in the Member State concerned | No | 
| E.8.5 | The trial involves multiple Member States | No | 
| E.8.6 Trial involving sites outside the EEA | 
| E.8.6.1 | Trial being conducted both within and outside the EEA | No | 
| E.8.6.2 | Trial being conducted completely outside of the EEA | No | 
| E.8.7 | Trial has a data monitoring committee | No | 
| E.8.8 | Definition of the end of the trial and justification where it is not the last
                        visit of the last subject undergoing the trial |  | 
| E.8.9 Initial estimate of the duration of the trial | 
| E.8.9.1 | In the Member State concerned years | 1 | 
| E.8.9.1 | In the Member State concerned months | 8 | 
| E.8.9.1 | In the Member State concerned days | 0 |