Thursday, July 16, 2015

Managing a patient with suspected ACS

We had a great discussion this morning about a patient presenting with classic concerning cardiac chest pain who had minimal cardiac risk factors, negative biomarkers and no significant ECG changes. One of the points we discussed was: Should this patient be treated for ACS prior to risk stratification? The answer is the same as for most of our decisions in medicine – it is a balance of risks vs benefits.

I will present a general approach to ACS. But remember – this is just a guide and all patients with chest pain are unique and can have subtle differences that can completely change management!

First, decide if the patient has an Acute Coronary Syndrome (ACS).
 Remember, ACS represents ‘acute’ plaque rupture and can include unstable angina, NSTEMI and STEMI. On your initial assessment, there are 4 things to consider when making this decision.
1)      History
2)      Physical Exam
3)      ECG
4)      Biomarkers
Use these tools to determine whether or not your patient has a high likelihood of ACS. If there is objective evidence of ACS (positive troponin, ECG changes) or if the likelihood of ACS is high then you will treat. If you do not think that there is an ACS or if the likelihood of ACS is low, look for another cause of chest pain. If you can’t find one, consider risk stratification as an outpatient (assuming there are no other concerning features).

And don't forget to include other diagnoses on your differential that may mimic ACS (ie. PE, pericardititis, etc...) and those conditions that are treated entirely differently (ie. aortic dissection).

If you decide that your patient has an NSTEMI or unstable angina, you can use various risk calculators to determine prognosis and decide on a strategy (conservative or early invasive).
 The TIMI risk score is a commonly used scoring system (http://www.timi.org/index.php?page=calculators) that predicts 14 day risk of mortality, new/recurrent MI or severe ischemia requiring urgent revascularization. The TIMI risk score calculator is based on 7 factors: age>65, 3 or more CAD risk factors, known CAD, ASA use in the past 7 days, 2 or more episodes of angina in 24 hours, ST changes >0.5mm, positive cardiac biomarker.

Key Point
: Remember, only use this risk calculator once you have decided your patient has or likely has ACS. It is not appropriate to use this scoring system to determine if your patient has ACS.

In general, use a conservative strategy for low risk (medication and non-invasive risk stratification) and use an early invasive approach for high risk (medication and angiogram within 24-48hrs). Patients diagnosed with ACS should receive ASA and anticoagulation along with the other cocktail of cardiac medications which we won’t go into in this blog.

So, how do you manage a patient with classic chest pain but no ECG changes and normal troponin?
 This patient could be labelled as ‘possible’ ACS. This is a grey zone that may lead to some confusion and maybe even variation in practice among internists.
  • If the ECG is non-ischemic and serial troponins negative and the patient remains free of chest pain BUT there is still a suspicion of ACS, a stress test is generally required to rule out unstable angina. This can be done as an inpatient (if intermediate/high risk features) or as an outpatient within 72 hours (if low risk features and no other concerns). Regarding acute medical management, the AHA guidelines suggest treating (ASA and anticoagulation) patients with definite or likely ACS.
  • According to AHA guidelines (2014), for patients with possible ACS but no objective evidence of myocardial ischemia (non-ischemic ECG and normal troponin):
    • It is reasonable to observe them in a telemetry unit with serial ECGs and troponin at 3-6 hour intervals.
    • It is reasonable to perform non-invasive risk stratification before discharge or within 72-hours of discharge.
    • In low-risk patients who can be discharged with outpatient risk stratification it is reasonable to give them daily ASA, short acting nitro and provide instructions about activity level and follow-up.

So the bottom line is: In general, patients with ‘possible’ ACS without objective ischemia (negative trops, normal ECG) do not require full anticoagulation prior to risk stratification. However, there are exceptions to every rule and these patients should be carefully assessed. The guidelines say that ‘likely’ or definite ACS should be treated. So how do we determine what to do for patients who fall in the grey zone between ‘possible’ ACS and ‘likely’ ACS? This is a case by case decision where you need to weigh the risks and benefits of therapy. This is where clinical experience and judgement are paramount.

Reference:
Amsterdam, Ezra A., et al. "2014 AHA/ACC guideline for the management of patients with non–ST-elevation acute coronary syndromes: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines." Journal of the American College of Cardiology 64.24 (2014): e139-e228.

Tuesday, July 7, 2015

Liver Cirrhosis

Thank you Team 3 for presenting a case of a patient with cryptogenic liver cirrhosis.  Cirrhosis is a very common diagnosis and we frequently care for patients with this disease. However, it is less common that we see patients with cryptogenic cirrhosis. This combination of a common condition with a less common etiology makes the case a perfect one for Morning Report!

A healthy liver is pink, smooth and filled with happy hepatocytes. The word ‘cirrhosis’ comes from the Greek word kirrhos which means ‘yellowish’ – describing the colour of the diseased organ. In addition to becoming discoloured, cirrhotic livers are firm, nodular and composed of fibrous tissue. This description of abnormal structure gives you a sense of how impaired the liver function can become! Here are six things to know about cirrhosis…
There is a long list of causes of cirrhosis but there is a short list of common causes:
     1. Alcohol
     2. Viral Hepatitis (C & B)
     3. Non-Alcoholic Fatty Liver Disease (NAFLD)
     4. Hemochromatosis
The other less common causes to think about include: Autoimmune, Primary Biliary Cirrhosis, Primary Sclerosing Cholangitis, Veno-occlusive disease, Wilson’s Disease, alpha-1 antitrypsin, medications (ie. methotrexate), right-sided heart failure and even celiac disease!  

Most patients remain asymptomatic until they develop decompensated cirrhosis which is characterized by the development of any of the following complications:
     - Variceal Bleed
     - Ascites
     - Encephalopathy
     - Spontaneous Bacterial Peritonitis
     - Jaundice
In addition to the acute complications of cirrhosis listed above, think about some of the other associated complications:
     - Hepatocellular carcinoma
     - Hepatorenal Syndrome
     - Osteoporosis

Bloodwork can provide clues that a patient has cirrhosis. Imaging and in some cases biopsy are used to confirm the diagnosis. According to the JAMA rational clinical exam, a platelet count of less than 160 increases the likelihood that the patient has cirrhosis. Remember, this is a sensitive finding – not specific! Other abnormal lab values in patients with cirrhosis include elevated bilirubin, elevated INR, reduced albumin and transaminitis. Abdominal ultrasound is the initial imaging modality of choice to assess for cirrhosis. Finally, a liver biopsy may be necessary to help determine an etiology.

Unfortunately, cirrhosis is irreversible so the management should focus on limiting or removing the precipitant and either preventing or dealing with the complications. This will commonly include managing ascites (diuretics, paracentesis, TIPS in select cases), SBP (antibiotics acutely and for prevention in certain cases), varices (non-selective beta-blockers, OGD with band ligation), encephalopathy (lactulose). Patients with decompensated cirrhosis should be considered for referral for liver transplant. There are many variables that go into deciding whether a patient is eligible for liver transplant including Model for End-stage Liver Disease (MELD) score, comorbidities, presence of complications and absence of contraindications.

A word about cryptogenic cirrhosis. This entity is not that uncommon, representing at least 5% of cases of cirrhosis. While the term cryptogenic implies that the cause is unclear, it is thought that many of these cases are due to unrecognized NASH, silent autoimmune hepatitis, non-B/C hepatitis or possibly from prior unreported alcohol use. Diagnosing cryptogenic cirrhosis requires a thorough history and extensive investigations. Biopsy can be used to help identify a cause of cirrhosis – particularly metabolic causes. The management is similar to that of other causes of cirrhosis. 

Finally, when diagnosing and/or managing cirrhosis - do not hesitate to refer to a gastroenterologist. UHN is home to world class hepatologists with interdisciplinary liver clinics that provide high quality care for these complex patients.

References:
1. Schuppan, Detlef, and Nezam H. Afdhal. "Liver cirrhosis." The Lancet 371.9615 (2008): 838-851.
2. Udell, Jacob A., et al. "Does this patient with liver disease have cirrhosis?."JAMA 307.8 (2012): 832-842.3
3. Caldwell, Stephen. "Cryptogenic cirrhosis: what are we missing?." Current gastroenterology reports 12.1 (2010): 40-48.