Plain-English summary
Most of the articles in this library are about things owners can learn to notice. This one is the exception, and it is worth reading for that reason.
Hypertrophic cardiomyopathy is the most common heart disease in cats. In its preclinical stage — meaning the cat appears entirely well — it produces essentially nothing an owner can observe. The REVEAL study followed 1,730 cats across 21 countries to find out what happens to those cats over time.
Among the 1,008 with preclinical disease, roughly three in ten developed congestive heart failure, a clot, or both. Nearly three in ten died a cardiovascular death. The cats that developed a complication then survived, on average, a little over a year.
There is no home observation that would have caught this. What catches it is a stethoscope and, when indicated, an echocardiogram.
What the study found
This was a retrospective, multicentre, longitudinal cohort study of 1,730 client-owned cats from 21 countries: 430 with preclinical nonobstructive hypertrophic cardiomyopathy, 578 with the preclinical obstructive form, and 722 apparently healthy cats. Cats were followed through medical record review and interviews with owners or referring veterinarians.
Among the 1,008 cats with preclinical disease, congestive heart failure, arterial thromboembolism, or both occurred in 30.5%, and cardiovascular death in 27.9%.
Risk accumulated over time. At one, five and ten years after study entry, the risk of congestive heart failure was 7.0%, 19.9% and 23.9%; for arterial thromboembolism it was 3.5%, 9.7% and 11.3%. Cardiovascular death risk was 6.7%, 22.8% and 28.3% at the same points.
There were no statistically significant differences between the obstructive and nonobstructive forms for cardiovascular morbidity, mortality, time from diagnosis to complication, or survival.
Cats that developed a cardiovascular complication had short survival afterwards — a mean of 1.3 years, with a standard deviation of 1.7. Prolonged longevity was uncommon: about 10% of preclinical cats reached 9 to 15 years.
The authors conclude that preclinical hypertrophic cardiomyopathy is a global health problem carrying substantial risk, and that this underscores the need for therapies and monitoring strategies that reduce it.
What this study cannot tell you
These figures describe cats already diagnosed with preclinical disease at participating centres. Cats reach a cardiology-capable centre because someone heard something, or because an owner pursued investigation — so this population is not a random sample of cats with the condition, and the risk figures may be higher than they would be for quieter disease found incidentally.
That matters for how alarmed to be. Other work in non-referred populations has reported lower rates of progression to death, and this study cannot settle that difference on its own.
The design is retrospective, with follow-up partly through owner and referring-vet interviews, which introduces recall and ascertainment variability.
The study also identifies no protective intervention. It measures what happened; it does not show that any monitoring strategy or treatment changes these outcomes — indeed the authors frame finding such strategies as the open need.
And nothing here supports any home screening. There is no owner-observable marker in this study at all.
What pet owners should track
The honest list is short, and mostly about not missing an emergency:
- Breathing at rest — rate and effort. A cat breathing fast or with visible effort while asleep or resting needs veterinary attention urgently, not tomorrow
- Sudden pain, crying, or weakness or paralysis in the hind legs — this is how a clot typically presents, and it is an emergency
- Whether a heart murmur or gallop has ever been noted, and at which visit — worth recording, because it is the usual route to diagnosis
- Any breed known to be predisposed, and any family history if you have it from a breeder
- If your cat has a diagnosis: the dates of echocardiograms and what changed between them
Keep routine veterinary examinations. That is not filler advice here — in this disease, the examination is the detection method.
What PAWai can help organize
PAWai can hold what the examinations found and when — the first murmur noted, the dates of any imaging, the medications and their changes — so a slow-moving cardiac history stays legible across years and possibly across clinics. PAWai does not screen for heart disease, cannot detect a murmur, and has no way to assess your cat's heart. This is the clearest example in the library of a condition where the record supports care but observation cannot substitute for it. If your cat is struggling to breathe or has suddenly lost use of its back legs, stop reading and call a veterinarian.
Disclaimer
PAWai organizes information and educates pet owners. PAWai does not diagnose conditions or recommend treatment. Always consult a licensed veterinarian for medical decisions about your pet.
Citation
Fox, P. R., Keene, B. W., Lamb, K., Schober, K. A., Chetboul, V., Luis Fuentes, V., et al. (2018). International collaborative study to assess cardiovascular risk and evaluate long-term health in cats with preclinical hypertrophic cardiomyopathy and apparently healthy cats: the REVEAL study. Journal of Veterinary Internal Medicine, 32(3), 930–943. https://doi.org/10.1111/jvim.15122