 When a blood clot formed in the legs dislodges, it travels up via the veins, through the heart and into the lungs, where it gets stuck. This obstruction forces the heart to work harder in order to pump blood through the lungs. If the obstruction is too great, the heart fails and the patient dies. This is a dangerous and common disease and causing more than half a million deaths a year in the EU alone. Despite this, treatments have remained largely unchanged for decades and still focus on removing the blood clot. As it turns out, however, the mechanical obstruction of this blood clot is only part of the problem. As agents released from this blood clot constricts pulmonary arteries and hereby worsens the overall obstruction. The question is then, can we reverse this vasoconstriction and prevent the heart from failing? Viagra is a well-known dilator of vessels, most commonly used to increase the blood flow to the male genitals. This effect may also be present in the lungs and that is why we aim to investigate if treatment with Viagra reduces the obstruction of the lungs and improves the function of the heart in pigs suffering from blood clots in the lungs. When we used the pigs in this experiment as the cardiovascular anatomy and size resembled that of humans. We draw blood and let it coagulate in plastic tubes. This allowed us to create blood clots similar to what we find in patients. Two of those were injected in a large vein on the neck from where the blood flow carried it to the lungs. Then animals were randomized to receive either placebo or Viagra. The obstruction of the lung was evaluated by catheters and the function of the heart by ultrasound. And what do we find? Well, after injecting these two blood clots, the obstruction increased greatly in the lungs. And when looking with the ultrasound, we saw that the heart was struggling. placebo didn't improve this, but in animals treated with Viagra, we saw a clear reduction in the obstruction of the lungs and when looking at the ultrasound, we saw the function of the heart had improved. So to conclude, treatment with Viagra reduces the obstruction of the lungs and improves the function of the heart in pigs suffering from blood clots in the lungs. And in the future, this simple and inexpensive treatment may prevent failure of the heart and improve survival of patients suffering from this common and dangerous disease. Thank you.