Analysis Highlights Importance of Risk Assessment in Cardiac Sarcoidosis

Analysis Highlights Importance of Risk Assessment in Cardiac Sarcoidosis

A new statistical analysis of Finland’s nationwide cardiac sarcoidosis (CS) registry found that sudden cardiac death plays a significant role in the outcome of CS patients, affirming the importance of risk assessment in this patient population.

The study, “Sudden death in cardiac sarcoidosis: an analysis of nationwide clinical and cause-of-death registries,” was published in the European Heart Journal.

CS is a type of inflammatory heart disease characterized by the clustering of white blood cells, or granulomas, in heart tissue. Granulomas that form in parts of the heart muscle that conduct electrical signals can cause irregular heartbeats (arrhythmias), and in some cases, heart failure.

Typically, CS is diagnosed following the detection of abnormal heartbeat patterns, such as atrioventricular block or ventricular tachycardia (fast resting heart rate), as measured on an electrocardiogram (ECG) or an echocardiogram (heart sonogram). However, in some cases, CS is only diagnosed following an autopsy after a sudden, fatal cardiac event.

Within the research community, there is an ongoing debate regarding the diagnosis and outcomes of these CS patients who are diagnosed after death — and who are thus considered clinically silent. 

To address this uncertainty, researchers in Finland analyzed CS patients’ records between 1998 and 2015, collected by the Myocardial Inflammatory Diseases in Finland (MIDFIN) study group, a nationwide clinical registry that curates CS patient information regarding diagnosis.

The team also analyzed Finland’s national cause-of-death registry to identify clinically silent cases of CS that ended in sudden cardiac death over the same period.

Researchers identified 351 cases of CS (mean age 52 years). The most common first sign of CS was atrioventricular block in 42% of patients; followed by left ventricular dysfunction with heart failure (17%); unexpected or aborted sudden cardiac death (14%), and sustained ventricular tachycardia (14%).

In total, 84 deaths were recorded over the study period; only 22 of them (26%) occurred in patients diagnosed with CS while they were alive.

Unexpected sudden cardiac death was found to be an important factor in CS outcomes, accounting for up to 80% of all fatalities in the CS cohort analyzed. Of note, sudden cardiac death from clinically silent CS was responsible for more than 40% of fatal CS cases.

Interestingly, the researchers found that almost two-thirds of CS deaths were caused by “hidden or misdiagnosed cardiac involvement.”

Researchers also estimated CS survival based on the data obtained. They reported that patients with CS have an 85% chance of living beyond five years after symptom onset, and a 76% chance of living beyond 10 years. With treatment, these estimates increased to 93% and 87% for 5- and 10-year survival, respectively. 

The data also showed a substantial increase in CS diagnosis over the time period analyzed, in addition to an increase in postmortem CS diagnosis and CS-linked deaths. According to the team, while the increase in diagnosis may be attributed to growing CS awareness and improvements in diagnostic tools, the increase in silent CS cases remains unclear.

Overall, the team concluded that “together, fatal and aborted [sudden cardiac death] constitute 14% of the presenting manifestations of CS,” and that “nearly two-thirds of all fatalities from CS are caused by undiagnosed granulomas in the heart.”

“The dominant role of SCD as the mode of death in CS emphasizes the importance of assessing the risk of fatal arrhythmias and planning preventive measures in each patient,” the researchers noted. 


  1. Angela Riley says:

    Have had blood tests ACE which show to be well above normal range. At present time waiting for a skin biopsy to confirm sarcoidosis. Had heart problems for last 10 years. Recently been getting burning in upper chest and throat that is helped by my GT spray.


    My 35-year-old son, an architect, died suddenly of CS at age 35 in 2014. He had bronchitis a month earlier and was given an antibiotic (Augmentin?). He was 5’11” and 135 pounds, married with a 3 ½ year old son. He biked and we thought he was in good general health.

    His only unusual behavior was occasional feinting from activity to sudden rest. This even included occasionally after sex.

    We have since learned that these occurrences might be a signal to a heart weakness that should have alerted us. Of course, we had never heard of sarcoidosis until his autopsy, and thought nothing of his feinting.

    As his father, it kills me to this day that we ignored his symptoms. We should have paid more attention.

    • Thomas, I just want to say, you must release yourself from blame as even if you had tried to find out what the problem was, it is very likely that the doctors would not have known in time. I was 49 when diagnosed and they still kept saying you are too young to have this. Sadly diagnosis is still a long bumpy road, especially with cardiac involvement. The disease, in many forms, often is elusive. It took over three years of extreme symptoms, countless tests, misdiagnosis, many nights spent in ER, accusations of phycological issues, then finally, near-death for my doctors to say we are 98% sure you have CS. After my pacemaker was inserted they still had to do more biopsies to rule out lymphoma. The truth about medicine is that diagnosis is the toughest part and technology has only recently advanced in distinguishing between the multitudes of diseases that mimic one another. If the deck is stacked in your favour you may be lucky. That means, specialists available in your location, informed doctors doing the right thing and referring to specialists, and medical coverage to financially support the necessary string of testing. Then there is TIME. Is time on anyone’s side in medicine? I had the same as your son. Chest infection. They weren’t even sure of what that was and near fainting with severe shortness of breath. Was very athletic and seemed exceptionally healthy. Sadly that worked against me in the doctor’s eyes. Thomas, and all of those out there that continue to blame yourselves, DON”T. The saying by Albert Einstein “the more I learn, the more I realize how much I don’t know”, applies to all things, especially medicine. Thomas, I can tell you are a magnificent father.

  3. Patty says:

    It took multiple doctors, and six years to figure out that it was sarcoid causing my arrhythmias. Before then I was blown off, dismissed, and even called a hypochondriac. Yet they still put an ICD in my chest, all while calling me these names lol. If I hadn’t kept pushing, I would never have gotten the testing that confirmed the diagnosis. I’m glad that I live in a large city with many doctors in it, because I’d most likely be dead if I lived in a small area with few doctors. Sarcoidosis is either missed completely or is misdiagnosed a LOT.

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