Cardiovascular disease is one of the leading causes of death in the developed world. A crucial tool in combating this illness is the rapid and accurate detection of early symptoms, before a heart attack occurs. Scientists in Portugal are taking steps towards a possible solution.

Isabel Santos leads a team at the Nuclear and Technological Institute, Sacavém, Portugal, who are developing radiotracers for early detection of heart failure. Now, the team have made and tested a series of water-stable rhenium and technetium compounds with pyrazole-based ligands, with encouraging results. A major advantage of these new compounds is their adaptability, offering opportunities to fine-tune uptake speed and bio-distribution in the future.

Radiotracers are compounds that contain a radioisotope, most commonly technetium-99m, which allows the progress of the compound to be tracked through the body. Ideally, a heart imaging radioisotope should have increased uptake in the heart, but Santos says the commercial complexes currently available are far from perfect, due to high liver and lung uptake.

Chris Orvig, an expert in medicinal chemistry at the University of British Columbia, Canada, said this research opens up new avenues in the design of heart imaging agents. 'Because of the versatility of pyrazolyl ligands, many new potential applications can be envisaged,' he said.

Santos believes that there are even more impressive results to come. 'I can say that in a short period we will have much better complexes for this application obtained by modifying the structure of the complexes. To get even better is a challenge that we are working on.'

May Copsey