The **OPTIMIZER Smart Study** is a research project to see if a special device called the **OPTIMIZER** helps people with certain heart problems. This study involves 620 people who already have this device, which is implanted to help their heart function better. The people in the study have a heart condition called **NYHA Class III heart failure** with a **left ventricular ejection fraction** between 25-45%. This means their heart doesn't pump blood as well as it should. The study will check if the device is safe and works well over a long time in real-life conditions.

• The study is open to men and non-pregnant women aged 18 or older with specific heart conditions.
• Participants must agree to follow all study steps and be available for the whole study period.
• If you have other heart issues or treatments, you might not be eligible to join.