Thursday, May 23, 2013

An Infected Heart Valve

I remember walking into this patient’s room like it was yesterday, even though it has been over a decade ago.  I remember this young thirty-some aged patient so well because of all of his tattoos he had, as well as his scraggly long hair tied into dreadlocks, which had seen better days.
“Hi, I’m Sharon and I’ve been asked to come and see you due to your being a new admission to our infectious disease service.  I see that the cardiology service has already seen you and they have asked for a cardiovascular consult.  Have you had your echocardiogram (ultrasound assessment of the heart, which shows its size, capability, ejection percentage, valve functions) yet?”
A ‘no’ answer came from the depths of the patient’s throat.  It was a clear, low bass voice that would have been wonderful and harmonious in a men’s quartet, if he had ever chosen to use it in a singing capacity. As he replied, he never moved from his position of laying on the hospital bed with the white sheet pulled up to his chin.  “When are you scheduled for it?”
Again this deep voice replied from underneath his dreadlocks, “I think they told me sometime later this day.  I think the doc from the cardiology service told me that they have to have one of the head docs do it, so they told me they would come and get me later to have it done.”
“Oh, okay, that means that one of the cardiology attendings will be doing it, so that means they will be sedating you, i.e. putting you to sleep.  Then they will put the ultrasound transducer down your throat.  You’ll be asked to swallow the transducer and then be quiet and not move, hence the use of sedation.”
“Umm,” came the reply from underneath the dreadlocks.
I swallowed hard, this patient interview was not going very well.  The patient was not exactly willing to engage in the needed conversation.   I was going to have to pull every shred of information out of him.
“Okay, how long have you been sick?”
Again, with little to no movement on his part, he answered, “about a couple of weeks.”
“Okay, what’s a couple of weeks to you?  Three weeks, four weeks, six weeks, what?”
“Umm, about a month I think.”
“Okay, when did your fevers start?
“About the same time as I started feeling bad, a month ago.”
“How high has your fever gone?”
“How am I supposed to know that?  I don’t take my temperature at home,” he replied somewhat perturbed.
“Hmm, alright.  Can I ask you whether you take any medications on a regular basis?”
 “No.”
“What do you do for a living?”
“I work as a day laborer when I feel like it, mostly carpenter work.”
“Ok, do you have any previous medical history, like any previous surgeries, or have asthma for instance?”
“Another ‘no’ came from beneath the dreadlocks.
“Do you use intravenous drugs at all, like inject heroin or some other street drugs?”
With that he grabbed his dreadlocks with both of his hands, pushing them aside from his face and partially sat up.  “Lady, I enjoy the highs I get from using my heroin.  Don’t you dare think of judging me for it, you hear me?”
“Sure do.”  
Seeing that I wasn’t getting very far with our new admission to the infectious disease service, I decided to change tactics.  I would just go read the cardiology history and physical and finish filling in the patient’s history from what they acquired.
“I need to do a physical exam on you, so would you mind sitting up for me?”
The patient reluctantly sat up as he crossed his legs.
I proceeded to do my physical exam.  The patient had numerous tattoos over his body, probably a total of ten.  One of them was a snake, another one was an anchor (typical of what former Navy vets have), another one was what I thought was probably a name of a former girlfriend.  Then there were several others.
The patient also had splinter hemorrhages underneath his dirty fingernails.  His hands were very calloused, which I assume was from his carpentry work.  His lungs were clear but his heart sounds had a definite 3/6 murmur heard over his tricuspid valve (one of the valves on the right side of the heart and can be involved in patients who have infective endocarditis.)  He also had numerous needle tracks on his forearms.
“Can you lay down for me so that I can do your abdominal exam, please?”
A grunt came from the patient’s throat as he laid back down on his hospital bed.
I found that he had a mildly enlarged spleen, with the rest of his exam being negative.
“I’m done now.  I’m going to go look up your blood work that they drew earlier on you while you were down in the emergency room.  I’ll be back later on with my attending.  Until then the nurse will be into hang another intravenous bag of antibiotics that they started on you while you were in the emergency room.  Do you have any questions for me?”
The patient grunted, no, so I left his room and walked over to the nurse’s station to look up his lab results.

Risk factors

Intravenous drug abuse
Prosthetic heart valve patients
Valvular heart disease (aortic stenosis, mitral valve prolapse, etc)
Intravascular catheters (usually used for cancer chemotherapy, hemodialysis)
Implanted cardiac devices (pacemakers, etc)
Surgical wounds

Presenting signs and symptoms of a patient with endocarditis:

Enlarged spleen
Fever (generally over 100.4 F)
Weight loss
New heart murmur
Skin lesions (raised macules or papules that have clotted off: called janeway lesions, or osler’s nodes which are small blood clots underneath the skin), splinter hemorrhages found on the nail beds, or submucosal hemorrhages found on the eyelids.
Eye changes can include roth spots which are swollen hemorrhages on the back of the eye (retina).
Presence of a systemic immune disease which can involve the kidneys or joint

Laboratory findings can include:

Anemia (low red blood cell count)
Increased white blood cell counts (these cells are responsible for fighting off infections)
Protein in the urine
Blood in the urine
Increased sedimentation rate (which is non-specific for an immune disease process)
Kidney insufficiency
Increased amount of circulating immunoglobulins
Positive blood cultures for a particular microbe typically associated with endocarditis
 
I pulled up the lab work that had been done on the patient just a few hours earlier.  The patient’s name was Michael and he had presented to the emergency room with a fever of 102 F and chest pain.  His lab work showed that he had an increased white blood cell count with the predominance of neutrophils (those are the specific white blood cells which fight off bacteria), a slightly low red blood cell count (mild anemia), his urine was normal, his sedimentation rate was markedly elevated at 100 (normal is below 20), and I noticed that there were two sets of blood cultures pending. 
I picked up the phone and called the microbiology lab. 
“Hi, this is Sylvia, how can I help you?”
“Sylvia, this is Sharon on the ID service.  Can you pull up this patient’s microbiology and tell me whether anything is growing out so far?”
Sylvia came back on the phone after pulling up his results.  “Sharon I just looked at his blood plates and nothing is growing out so far.  We won’t be doing a gram stain until we see some growth.  We’ll probably have some initial results tomorrow morning when your service meets with us in the morning, like you usually do.”
“Ok, Sylvia, thanks for looking.”
“Alright, see you in the morning.”
The following morning the microbiology lab did indeed have their initial results for us.  The culture plates had started to grow out what we called ‘purple clusters.’  This meant that the patient had a gram positive cocci growing in his blood.  This was typical of either streptococcus or staphylococcus.  So the patient was indeed on the right intravenous antibiotics, he had been started on Unasyn (a penicillin) and Gentamicin (an aminoglycoside). 
I went upstairs after microbiology rounds and looked up the patient’s echocardiogram that had been done late yesterday afternoon.  His echocardiogram had been done via a transesophageal approach.  It showed that he had a large vegetation on his tricuspid valve (one of 4 heart valves), with a slightly lower than expected ejection fraction (the ability of the heart to eject blood out into the system).  His ejection fraction was 45%, with a normal being above 60%.

Microbiology:

Staphylococcal species (42%)
Streptococcal species (40%)
Gram negative bacilli (2%)
Enterococci (which used to be classified as streptococcus group D)
Fungi  (2%)
Culture negative bacteria (8%)
Other bacterial organisms (6%)

Diagnosis:

Presence of any 2 major criteria or 1 major with 3 minor criteria, or all 5 minor criteria:

1) persistently positive blood cultures of organisms typical for endocarditis;
2) endocardial involvement (new valvular regurgitation or positive echocardiogram);

Minor criteria:

1)    Predisposing condition or IVDA
2)    Fever
3)    Embolic vascular phenomenon
4)    Immunologic phenomena (i.e. glomerulonephritis, rheumatoid factor)
5)    Positive blood cultures not meeting major criteria

Patients who are suspected of having infective endocarditis will end up having a transesophageal echocardiogram (ultrasound transducer placed in the patient’s esophagus or swallowing tube) instead of a transthoracic (ultrasound transducer placed on the patient’s chest wall) echocardiogram.  The reason for this is the lack of sensitivity with the transthoracic echocardiogram (i.e. 50-80%).  The sensitivity of using a transesophageal echocardiogram is 90-94%. 
Using the transesophageal approach involves sedating the patient so that they will be comfortable, during the procedure with having the transducer placed in their esophagus.
Typical findings on the echocardiogram of a patient who has infective endocarditis can include: a new vegetation found on a valve, paravalvular abscess, valve leaflet perforation or dehiscence. 
I went into check on Michael before my team began its daily rounds. 
“Hi, Michael.  How was your night?”
He grunted, “okay, I guess.” 
“Any problems with the antibiotics?”
“No.”
“Your temperature chart shows your fever is coming down, that’s nice."
“Hmm.”
“Did the cardiology service tell you the results of your echocardiogram?”
“Yeah, they told me that there’s something wrong with one of my heart valves.  That’s all I remember.”
“Well, with your history of using IV drugs, the positive results we found on your blood cultures this morning which is growing out a gram positive cocci, most likely a skin bug, and the presence of a new vegetation on your tricuspid valve means that you have what is called endocarditis.  This means that you have an infected heart valve which you acquired from your heroin use.  You’ll have to be on IV antibiotics for six weeks.  The cardiology service will also decide whether you need to have the valve replaced, i.e. whether you will need to have open heart surgery, this will be based on how well you do and whether you end up  with heart failure. 
“Umm,’ was his response.
“Okay, well can you sit up for me so that I can listen to you?”
Again, he reluctantly sat up for me as he crossed his legs.
I didn’t find any change on his physical exam.  I left his room and proceeded to see the other patients I was assigned so that I could be ready for our daily patient rounds.  On rounds my attending didn’t have anything else to add to Michael’s care, so we left him alone. 
A day later I was at microbiology rounds again and they advised us (my attending and my fellow colleagues) that my patient was growing out Staphylocccus aureus.  With this information, Michael was on the right antibiotics. 
I went up later on and found out that his fever was again on a downward trend and he had started to eat again, his appetite had finally returned.  He must have started to feel better because this time I found him sitting up by the side of his bed talking to a friend sitting in the bedside chair.    
We kept him in the hospital for two weeks, until he was done with his two weeks of gentamicin.  His heart function didn’t worsen as he responded to the antibiotics.  But we still needed to have him continue his intravenous antibiotics (Unasyn) for another four weeks.  So with the knowledge that we would need to keep a close eye on him and knowing that he needed help with his drug abuse, we asked the discharge social worker to find a drug rehab placement for him.  Michael agreed to be placed at the rehab facility, which allowed us to know that he would stay on his IV therapy. 

Treatment:

IV antibiotics and/or surgery:

Based on the patient’s microbiology and the sensitivity of the bacteria (typically bacteria although it could be a fungal infection) the patient’s is given at least 4-6 weeks of IV antibiotics to address the infection.  The duration of IV antibiotics is based on the sensitivity of the organism to the antibiotic and the rate of which it is typically known to be killed. 
For gram positive organisms (such as Staphylococcal, Streptococcus) patients are given a penicillin with gentamicin (for the first two weeks) or Vancomycin with gentamicin.  Those patients who have a gram negative bacteria they are generally treated with ampicillin with gentamicin. 

Most patients (50%) will end up needing to have open heart surgery during their initial hospitalization.  Indications for surgery include:

1)    severe left sided valvular regurgitation, fistula formation and/or resultant heart failure
2)    evidence of persistent infection despite appropriate antibiotic therapy
3)    presence of a prothetic valve
4)    presence of an intracardial abscess or fistula
5)    recurrent emboli being thrown from a large infected vegetation on the heart valve

Even today with all of our advances in medicine and surgical options there still remains a high mortality (20%) for patients diagnosed with infective endocarditis.  Mortality these days is generally due to the patient resultant heart failure.
 
 The cardiology service and us followed Michael over the next several weeks.  He stayed in his rehab facility and actually attempted to stop his heroin use.  He finished out his six weeks of intravenous antibiotics.  We ended up seeing him at 3 months after his discharge and at that time his tricuspid valve was healing, his heart murmur was less pronounced.  He was still being followed by the cardiology service to make sure that his heart function did not worsen.  But no one was surprised when he didn’t show up for his one year follow-up with the cardiology service, so what happened to him at this time, was anyone’s guess.

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