Cat cardiology

RE: Cat cardiology

Roland Bulkyn-Rackowe — Thu, 30 Nov 2017 15:57:27 GMT

[quote user="Martin Atkinson"]

[quote user="Anthony Dennison"]However, if I was just taking a blood sample for NT-proBNP, with my practice's pricing it works out as a similar cost to a scan?[/quote]Cardiopet from Idexx costs £36.10 + VAT. I would venture that someone is grossly over marking-up on lab fees or grossly undercharging for a scan given the cost of the equipment and skill involved.

[/quote]

I have varying costs for scans, from £30 (we do this along with blood and urine tests as a component of a "pre anaestheic screen" for older cats) to £180 (much more detailed). I started by screening rescue cats for free and since have had plenty of practice with owned cats. If you scan enough the machine pays for itself. I don't really run many proBNP tests as they were't available when I started to scan and am comfortable with the machines I've used.

If a cat is flagged up with problems with the pre anaesthetic scan I offer either a referral for ultrasound or a more comprehensive scan in our practice.

RE: Cat cardiology

David Mills — Tue, 28 Nov 2017 14:46:27 GMT

[quote user="Anthony Dennison"]Yes, I think if there is dynamic outflow tract obstruction pimobendan is contraindicated, but I'm sure David will give the correct terminology. [/quote]

This is a case where terminology is important.

There are two possible causes of outflow tract obstruction.

1. "HOCM" where there is focal thickening of the outflow tract in cats in the IVS wall distal to the aortic valve.

2. SAM - where the mitral valve is sucked into the outflow tract during systole.

I cannot understand how, physiologically, pimobendan would worsen 1), but can understand how it would worsen 2) (the so called shower-curtain effect, of Bernouilli effect). In fact, I would have thought it would improve 1) (unless there was concurrent mitral valve regurgitation). The work so far shows that HOCM cats benefit from pimobendan.

[quote user="Martin Atkinson"]so it might be better to work on a cut off of 350.[/quote]

Pure conjecture.

RE: Cat cardiology

Martin Atkinson — Tue, 28 Nov 2017 10:23:33 GMT

RE: Cat cardiology

Anthony Dennison — Mon, 27 Nov 2017 19:30:59 GMT

[quote user="Martin Atkinson"]IMO the advantage of NT-proBNP over echo is ease and cost, especially if you're already taking the blood[/quote]

However, if I was just taking a blood sample for NT-proBNP, with my practice's pricing it works out as a similar cost to a scan?

RE: Cat cardiology

Martin Atkinson — Mon, 27 Nov 2017 18:58:40 GMT

[quote user="Anthony Dennison"]What would be the appropriate approach in a case like this with no clinical signs?[/quote]You know you're going to get different answers to this but it does depend on how old this cat is. If it is, as suspected from the fact it has CKD, into its teens and had the murmur for years then it is probably unlikely this murmur is significant - unless it's anaemic! IMO the advantage of NT-proBNP over echo is ease and cost, especially if you're already taking the blood (don't forget to take a larger EDTA sample because that's what you need for the test). If it is over 270 then you might like to suggest echo but don't forget that renal disease can cause a rise in NT-proBNP so it might be better to work on a cut off of 350. If it is diagnosed with cardiac disease then Benazepril I would suggest is a better bet than Semintra because you're potentially killing 2 birds with one stone.

RE: Cat cardiology

Anthony Dennison — Mon, 27 Nov 2017 18:19:07 GMT

Considering what has been discussed previously, I had a cat in for it's booster earlier.

Has a grade 3/6 systolic murmur. Has had it for years. Very active cat, constantly hunting, constantly fighting. No current signs of CHF according to the owner (and she is VERY vigilant). Cat has CKD and is on RC Renal and Semintra.

I offered either testing NT proBNP (I was planning on taking a blood sample to check renal parameters anyway) or an echo to check left atrial size. What would be the appropriate approach in a case like this with no clinical signs?

RE: Cat cardiology

Richard Carter — Mon, 27 Nov 2017 12:55:39 GMT

Aware of the contra-indication which is why cats initially were a no-go area for the data sheet given that most would have hypertrophic cardiomyopathy. However it now appears the remodelling and changes of dynamics can adjust and cope with the altered muscle contractions and that cats in a clinical setting do very well

RE: Cat cardiology

Anthony Dennison — Mon, 27 Nov 2017 09:37:20 GMT

[quote user="Martin Atkinson"][quote user="Richard Carter"]Pimobendan definitely now in my list of favourite drugs to have been invented and now struggling to find a reason for using ACEi in heart cases.[/quote]Care needs to be taken with Pimobendan in cats as highlighted with a case I recently referred to the QMH for echo and the comment was: 'Regarding the use of pimobendan, ****** has evidence of obstruction to blood flow in her mid-ventricle during systole (the likely source of her murmur). We do not use pimobendan in these cases for fear of worsening this obstruction and causing hypotension'. [/quote]

Yes, I think if there is dynamic outflow tract obstruction pimobendan is contraindicated, but I'm sure David will give the correct terminology. The cat cardiology lectures at LVS were good for little things like that.

RE: Cat cardiology

Martin Atkinson — Sat, 25 Nov 2017 10:49:59 GMT

[quote user="Richard Carter"]Pimobendan definitely now in my list of favourite drugs to have been invented and now struggling to find a reason for using ACEi in heart cases.[/quote]Care needs to be taken with Pimobendan in cats as highlighted with a case I recently referred to the QMH for echo and the comment was: 'Regarding the use of pimobendan, ****** has evidence of obstruction to blood flow in her mid-ventricle during systole (the likely source of her murmur). We do not use pimobendan in these cases for fear of worsening this obstruction and causing hypotension'.

While I would be happy to use Pimobendan in most cats, this highlights that they should be used with caution and in this case ACEi is most appropriate (it was already on Benazepril as a preemptive strike) and shows the advantage of echo but IMO one of the few cases it has a diagnostic advantage in cats.

Also retires to bunker pending brickbats from DM!

RE: Cat cardiology

Richard Carter — Fri, 24 Nov 2017 19:13:15 GMT

As a lowly GP who doesn't know about fractional shortening in a cardiac echo, can I just comment I now have about 10 cats on pimobendan (with off-licence consent as we are being politically correct given the temperature of the above discussion ) who/that presented in CHF with tachyarrythmias, most with hypertrophic but two with dilative cardiomyopathy and all are doing so well they are almost off diuretics, heart rates stabilised down to 100 - 120bpm, murmurs reduced in intensity, active, eating, putting on weight.

Pimobendan definitely now in my list of favourite drugs to have been invented and now struggling to find a reason for using ACEi in heart cases. Still use for renal cases. Seems to me furosemide and ACEi essentially doing the same thing on reducing sodium content and furosemide is more effective. Use frusol solution in cats as can manipulate the dose better than fractions of tablets.

will try sid dosing but these cats are on 1/2 of 1.25mg bid without comment from owners.

retreating to my bunker again

RE: Cat cardiology

David Mills — Fri, 24 Nov 2017 14:19:32 GMT

[quote user="robloxley"]I assume Kate wondered what clinical evidence you had to use aspirin rather than clopidogrel?[/quote]

There's no evidence aspirin is superior as a preventative (pre-any-ATE). But there is evidence that aspirin at a low dose in cats affects clotting by reducing thromboxane levels and platelet aggregation - whether this translates into a beneficial clinical effect, we don't know. Clopidogrel may be better - but we do not, to my mind, have sufficient evidence to say this. The questionable clinical effect is one of the reasons why I use a lot less aspirin (and hardly ever clopidogrel - that's because I euthanase 99.9% of ATEs, but that's another discussion) than I used to.

[quote user="robloxley"]shat is the current feeling on SID versus BID pimobendan in cats?[/quote]

Pharmcologically, pimobendan has a much longer half life in cats than dogs (about twice as long) so theoretically once a day should be adequate. However all the studies into it in cats use twice a day, I'm not sure why. I used 1.25mg/cat/24h - I recommend once a day for ease, but some clients choose to split the dose.

I've also moved over, in the right circumstances, to owners using injectable dimazon SQ at home instead of frusemide tablets. The injectable has twice the bioavailability as oral so you can use a lower dose.

RE: Cat cardiology

Rob Loxley — Fri, 24 Nov 2017 13:50:18 GMT

but you did say [quote user="David Mills"]I will use aspirin rather than clopidogrel. This is not a dogmatic choice, but a holistic one, and one based in evidence[/quote] I assume Kate wondered what clinical evidence you had to use aspirin rather than clopidogrel?

I do get your point on amount of tablets to give, and sometimes this is a factor; shat is the current feeling on SID versus BID pimobendan in cats?

RE: Cat cardiology

David Mills — Fri, 24 Nov 2017 11:27:49 GMT

[quote user="Kate Richardson"]if clopidogrel has been shown to be superior to aspirin in the fate study, what evidence do you base your decision on? [/quote]

See above for discussion of why extrapolating this to primary prevention is difficult.

There is a good discussion of the evidence for aspirin here:

http://journals.sagepub.com/doi/abs/10.1177/1098612X12451547?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed&

I also prefer to minimise tableting in cats with heart disease.

I accept I may well be wrong in this, but my reading of the current evidence, and consideration of the patient (and compliance) means this is my approach. I don't think we have enough evidence to say clopidogrel is better at primary prevention, given the restricted nature of the FATCAT study.

RE: Cat cardiology

Kate Richardson — Thu, 23 Nov 2017 21:09:45 GMT

David Mills

"Given the clinical nature of heart disease, and cats generally, I will use aspirin rather than clopidogrel. This is not a dogmatic choice, but a holistic one, and one based in evidence."

Explain further- if clopidogrel has been shown to be superior to aspirin in the fate study, what evidence do you base your decision on? Genuinely interested

RE: Cat cardiology

Anthony Todd — Thu, 23 Nov 2017 16:52:10 GMT

Fortunately none of MY clients never had to stumble across a lot of the threads on this platform!!

Particularly this one.

RE: Cat cardiology

Martin Atkinson — Thu, 23 Nov 2017 16:17:51 GMT

[quote user="Bob Russell"]Would be a very good discussion if it was not for the nastiness being shown.[/quote]Don't take it too seriously Bob, its just a playground tussle!

RE: Cat cardiology

Bob Russell — Thu, 23 Nov 2017 15:53:00 GMT

Would be a very good discussion if it was not for the nastiness being shown.

RE: Cat cardiology

Martin Atkinson — Thu, 23 Nov 2017 10:35:54 GMT

[quote user="David Mills"]are you going to show some humility and say so? [/quote]

RE: Cat cardiology

David Mills — Thu, 23 Nov 2017 10:18:02 GMT

[quote user="Martin Atkinson"]He told me that aspirin is a total waste of time, [/quote]

Ah, who needs EBM when we have eminence-based medicine? How irresponsible.

[quote user="Martin Atkinson"]there is a large risk of causing GI irritation/ulceration.[/quote]

We're talking about cats. Apsirin was very well tolerated in the FAT CAT study, and showed the same rate of adverse effects as clopidogrel.

[quote user="Martin Atkinson"] I think we can pretty well say that aspirin is useless [/quote]

You just never learn do you?

[quote user="Martin Atkinson"]I find it rather amusing and sad that you seem to gain pleasure from trying to prove me wrong [/quote]

Oh darling, proving you wrong, repeatedly, comes so easily it is no more pleasurable than allowing a fly a few more seconds of flight rest before whacking it. There is no trying about it - are you going to show some humility and say so?

There is a slightly more serious issue here of pronunciations to the forum which are, well, wrong. See it as me carrying out a public service.

RE: Cat cardiology

Martin Atkinson — Thu, 23 Nov 2017 10:08:14 GMT

[quote user="Michael Woodhouse"]Has it now? Will someone tell NICE[/quote]Well its taken me suffering from AF and seeing a cardiologist for us to have have this information so you should be grateful to me.

He told me that aspirin is a total waste of time, not worth taking even for those long haul flights it is so much mooted for (a pair of compression socks is a better bet) and there is a large risk of causing GI irritation/ulceration. I have been put on Dabigatran which is one of the new generation NOAC anti-coagulants.

[quote user="robloxley"]Do we have reason to suggest that if we want to pre-emptively give an anti-thrombotic (rather than treat a cat that has had an ATE) that clopidogrel would not be a better choice than aspirin?[/quote]So I cannot say that clopidogrel is effective in cats but I think we can pretty well say that aspirin is useless and even if it worked dabigatran it is probably too expensive.

[quote user="David Mills"]the one amusing thing to come out of this is that Atko's essential truths have been systematically dismantled by myself and others, using the cold hand of evidence, and he's been made to look somewhat silly.[/quote]I find it rather amusing and sad that you seem to gain pleasure from trying to prove me wrong and still exhibiting schoolyard behaviour. Hardly the way to go about winning the hand of one of daughters.

RE: Cat cardiology

David Mills — Thu, 23 Nov 2017 09:56:49 GMT

[quote user="Thomas Johnson"]A very informative post, but my reading of the abstract of the above paper is that clopidogrel is better than aspiriin, am I missing something?[/quote]

The FAT CAT study looked specifically at one question (it is a good paper) - whether cats that had had ATE would avoid another one for longer when taking clopidogrel compared to aspirin. They did.

The authors conclude "It is possible that cats who survive a CATE event are somehow different from the broader population of cats with underlying heart disease so it is unknown if the superiority of clopidogrel over aspirin is applicable to primary prevention of CATE"

They reasonably say that "clopidogrel would appear to be a reasonable clinical choice for primary thromboprophylaxis in cats determined to be at risk for CATE" - something no-one is arguing, and what we "knew" anyway.

My issue was with someone on here saying clopidogrel is superior to aspiring for primary prevention, that aspirin was useless, and it was "already too late" to start anti-thrombotics once a CATE had occurred, none of which are true.

This highlights one of the recurring issues on this thread, and the profession more widely when it comes to "evidence". People will throw about the FAT CAT study as proof clopidogrel is superior, always. It may well be, but the study - like all good clinical studies - does not aim to answer that question, but looks specifically at cats that have had a previous CATE. The extrapolation to primary use is difficult as cats at that stage may have different derangements in their clotting cascade that are better suited to aspirin therapy.

Given the clinical nature of heart disease, and cats generally, I will use aspirin rather than clopidogrel. This is not a dogmatic choice, but a holistic one, and one based in evidence. When such time new evidence emerges, I will change my position. However, it is irresponsible to be thrwoing around "essential truths" based on very little - the one amusing thing to come out of this is that Atko's essential truths have been systematically dismantled by myself and others, using the cold hand of evidence, and he's been made to look somewhat silly.

RE: Cat cardiology

Rob Loxley — Thu, 23 Nov 2017 08:48:04 GMT

[quote user="David Mills"]The FAT CAT study looked at cats that had suffered ATE, not its pre-emptive use.[/quote]

Do we have reason to suggest that if we want to pre-emptively give an anti-thrombotic (rather than treat a cat that has had an ATE) that clopidogrel would not be a better choice than aspirin?

RE: Cat cardiology

Thomas Johnson — Thu, 23 Nov 2017 08:34:43 GMT

[quote user="David Mills"]

Incorrect. The FAT CAT study looked at cats that had suffered ATE, not its pre-emptive use.

https://www.ncbi.nlm.nih.gov/pubmed/26776588

Interestingly, upto 30% of cats with ATE have no underlying heart disease. But cats with cardiomyopathy can display a mikly hypercoaguable state so aspirin or clopidogrel appear to be theoretically indicated, though we cannot say one is better than the other. There is no evidence that either reduces time to first ATE.

[/quote]

A very informative post, but my reading of the abstract of the above paper is that clopidogrel is better than aspiriin, am I missing something?

RE: Cat cardiology

Michael Woodhouse — Thu, 23 Nov 2017 01:06:12 GMT

[quote user="Martin Atkinson"](aspirin has now been shown to be useless in humans)[/quote]

Has it now? Will someone tell NICE (I've made all the recommendations to use 'useless' aspirin red to make it easier to spot them):

Basis for recommendation

These recommendations are in line with UK and European guidelines on the use of antiplatelet treatment for secondary prevention of cardiovascular disease [British Cardiac Society et al, 2005; NICE, 2010b; NICE, 2010c; Intercollegiate Stroke Working Party, 2012; Perk et al, 2012; SIGN, 2013].

Which antiplatelet treatment

Which antiplatelet treatment should I prescribe for secondary prevention of cardiovascular disease?

The indications for the different antiplatelet drugs are:

- Myocardial infarction: treat long-term with low-dose aspirin (75 mg daily for most people). Clopidogrel (75 mg daily) is an alternative if aspirin is contraindicated or not tolerated.
  - For people with acute coronary syndrome without ST-segment elevation:
  - Following the acute event, a combination of low-dose aspirin (usually 75 mg daily) plus either clopidogrel 75 mg daily or ticagrelor 90 mg twice a day is given for 12 months.
  - Low-dose aspirin is then continued alone long-term.
  - For people with acute coronary syndrome with ST-segment elevation:
  - Following the acute event, a combination of low-dose aspirin (usually 75 mg daily) plus either clopidogrel 75 mg daily or ticagrelor 90 mg twice a day is recommended.
  - If clopidogrel and aspirin were used, continue these for at least 1 month. If aspirin and ticagrelor were used, continue these for up to 12 months.
  - Low-dose aspirin is then continued alone long-term.
- Coronary or carotid interventions, such as stenting
- - In general, low dose aspirin (75–300 mg) in combination with one of the following antiplatelets is initiated in secondary care:
  - Clopidogrel 75 mg daily, or
  - Prasugrel 10 mg daily (or 5 mg daily if the person weighs less than 60 kg, or if the person is 75 years of age or older), or
  - Ticagrelor 90 mg twice a day.
  - Treatment is usually continued for up to 12 months after the procedure (unless otherwise specified by the specialist). After the stated period of treatment, antiplatelet treatment is continued with low-dose aspirin alone.
- Ischaemic stroke and transient ischaemic attack
- - Clopidogrel (75 mg daily) is the preferred antiplatelet.
  - If clopidogrel is contraindicated or not tolerated, give modified–release dipyridamole (200 mg twice a day) combined with low dose aspirin.
  - If both clopidogrel and modified-release dipyridamole are contraindicated or not tolerated, give aspirin alone.
  - If both clopidogrel and aspirin are contraindicated or not tolerated, give modified-release dipyridamole alone.
- Peripheral arterial disease
- - Clopidogrel 75 mg daily is the preferred antiplatelet.
  - If clopidogrel is contraindicated or not tolerated, give low dose aspirin alone.
  - If both clopidogrel and aspirin are contraindicated or not tolerated, give modified-release dipyridamole alone.
- Multivascular disease (people with cardiovascular disease who have disease in more than one vascular site)
- - Clopidogrel 75 mg daily is the preferred antiplatelet.
  - If clopidogrel is contraindicated or not tolerated, give aspirin alone.

https://cks.nice.org.uk/antiplatelet-treatment#!scenario:1

RE: Cat cardiology

David Mills — Wed, 22 Nov 2017 20:46:53 GMT

[quote user="Robin Grimmer"]This used to be a recommended treatment but post pimobendan this doesn't seem to be done much[/quote]

Depends who the clinician is I suppose. Plenty still do.[quote user="Robin Grimmer"]Re beta blockers in cats with HCM I was specifically referring to cases secondary to hyperthryoidism.[/quote]

This doesn't make sense. If you control the hyperthyroidism the heart rate decreases. The HCM is pretty much indistinguishable from naturally occurring. So there wouldn't be an indication.

[quote user="Robin Grimmer"]Are Ca channel blockers still recommended for cats with HCM?[/quote]

Diltiazem is still licensed but the evidence is weak and flawed, most of it from the 90s dealing with surrogate outcomes. It's no longer a commonly used drug, can't remember the last time I used it.