What Happens If The Circumflex Artery Is Blocked

Imagine driving through a tunnel. On Monday, you encounter a pile of rubble. There is a narrow gap, big enough to drive through. On Tuesday, youre driving through the tunnel and find a giant boulder blocking the entire tunnel. No gaps whatsoever. Now translate those examples to your health. The tunnels are the arteries that carry blood to your heart. The rubble and boulders are blockages that can lead to problems – shown through symptoms. Blocked tunnels aren’t good for traffic flow, and blocked arteries aren’t good for your heart. In cardiology, the boulder is called a Chronic Total Occlusion (CTO). It means the artery is completely blocked. This occurs in 15% to 20% of patients who have heart disease. Sometimes there has been a complete blockage for many months or even years. However, only about 3% to 5% of these patients undergo a stent or bypass procedure, so theres a real need to help these untreated patients. Failure to diagnose and treat a CTO can lead to symptoms and impact your quality of life.

Artery blockages are not created equal. Treatment of an artery that is 97% blocked is much easier than treating one that has been 100% blocked for a long time. The symptoms – chest pain, tightness and shortness of breath – can be similar, though. Sometimes, when arteries become completely blocked, a new blood supply develops around the blockage. This new blood supply, called collaterals, wont deliver as much blood to your heart. This can lead to those same symptoms of chest pain and shortness of breath. If you have these symptoms, a stress test can help determine if they are caused by a blockage in an artery or something else. The first step is to see a doctor.

Fifteen years ago, we had one way to treat Chronic Total Occlusions – try to probe a wire through the blockage from the front. These procedures had a 70% to 75% success rate, which kept some doctors from recommending treatment.

Today, we have more treatment options. We can sometimes go around the blockage or work backward through the heart. Were now seeing success rates of 90% to 95%.

If you are told that you have an artery that is 100% blocked, it’s important to know that it can be treated.

Patients should understand that successful treatment will relieve symptoms and will result in a better quality of life. Clinical studies are still under way tracking the long-term outcomes of this type of treatment, but we are seeing very consistent benefits so far.

When you need treatment for a Chronic Total Occlusion, most doctors will refer you to a CTO Center. UT Southwestern is positioned to become a Center of Excellence for CTO treatment.

What are the signs of a blockage in the circumflex artery? Lack of blood flow from narrowed, blocked arteries can cause a type of chest pain called angina. This type of angina can lead to a heart attack, which is a medical emergency. You should call 911.

Follow-up consisted of three stages. The first stage was a questionnaire sent to patients 2 years after myocardial infarction. The next stage, if the patient did not send the questionnaire back, was telephone contact with the patient or with his family. Missing data were collected from the Provincial Administration Office. Information concerning endpoint was obtained in 100 % of the cases. The office provides information concerning death of a person; however, the cause of death remains unknown. The study was approved by the local Bioethics Committee.

This study has a few limitations. First is the relatively small number of patients. However, to achieve a homogenous group of patients, we studied 3121 consecutive patients with STEMI. The observed correlation could be confirmed in the future with prospective and larger population studies. Moreover, we used overall mortality as an endpoint, due to the fact that it was not possible to define the cause of death in all cases. Thus, we are not certain whether all reported deaths were cardiovascular. Concluding, significant narrowing of the Cx leads to worse outcomes than narrowing of the RCA in patients with STEMI treated with PCI of the LAD. Thus, patients with Cx narrowing should be treated more cautiously and require special attention after anterior STEMI treated with PCI of LAD.

Over the past decades, the outcomes in patients with ST-elevation myocardial infarction (STEMI) have improved [1]. However, putting aside good early results, late outcomes are still not satisfactory, especially in patients with non-ST-elevation acute coronary syndromes in whom late prognosis is worse than in STEMI patients. Thus, searching for predictors of long-term mortality is still justified. Location of infarction is established as one such predictor. Inferior wall STEMI is thought to have a better long-term prognosis than anterior STEMI [2]. However, inferior STEMI may be the result of either circumflex artery (Cx) or right coronary artery (RCA) disease, leading to different outcomes. Nevertheless, significant narrowing of the Cx frequently does not present with ischemic signs on the ECG, even if the artery is occluded. Such a phenomenon can lead to the wrong qualification and delayed angiography during STEMI or stable coronary artery disease [3]. Hence, inadequate treatment of the narrowing of this artery can lead to worse outcomes. The number of arteries affected by atherosclerosis is an additional factor influencing the outcome. Moreover, prognosis may be affected by coronary artery dominance. It has been reported that left coronary artery dominance in the case of significant coronary artery disease is related to worse prognosis [4]. Moreover, the issue whether Cx or RCA disease is worse, still remains unclear. Additionally, different outcomes related to Cx or RCA stenosis in patients with anterior STEMI treated invasively have not been confirmed. Accordingly, the aim of this analysis was to establish if narrowing of the Cx is related to diverse outcomes in comparison with the narrowing of RCA in patients with STEMI treated with percutaneous coronary intervention (PCI) of the left anterior descending artery (LAD).

It should be borne in mind that disease affecting different segments and arteries may lead to diverse outcomes. The location of a lesion in the LAD could be of key importance in the prognosis of patients with STEMI, due to the fact that the occlusion of the proximal LAD is related to more extensive heart muscle damage and therefore worse outcomes [10]. Nevertheless, the location of LAD occlusion did not present with differences in our analysis, which is also reflected in the lack of differentiation of the ejection fraction of the left ventricle, a direct exponent of the level of impairment of left ventricle. The Cx artery is the least frequent culprit vessel among patients treated invasively for STEMI [3]. Furthermore, patients with Cx occlusion are less likely to present ST-segment elevation, hence they remain underdiagnosed. Nevertheless, it has not been established if the outcome differs depending on whether the stenosis is in the Cx or RCA, in patients with anterior STEMI treated invasively. In the presented study, we found that patients with Cx narrowing present with worse outcomes. The explanation for such an observation has not been clearly defined. Patients with LAD narrowing usually have collateral circulation from the RCA artery. Thus, RCA narrowing in patients with anterior STEMI should lead to worse compensatory backflow to the occluded LAD, affecting the outcome more than Cx stenosis. Moreover, some studies suggested that Cx-related STEMI is usually smaller compared with RCA-related STEMI [14]. Such an observation should not be referred to the general population of patients with STEMI until coronary artery dominance is taken into consideration. Veltman et al. [15] reported that the prognosis of STEMI patients during a 30-day follow-up is worse in the case of left coronary artery dominance. According to the cited observation, discrepancies in the prognosis may result from the dominance of one artery and not directly from the type of the artery—Cx or RCA. In the presented study, the prevalence of right dominance was similar in the two groups, hence it may not constitute an explanation for the differences in mortality. On the other hand, the differences in mortality may stem from the fact that Cx stenosis in patients with anterior STEMI can be interpreted as an equivalent of left main disease, leading to worse outcome. Nevertheless, all the patients in our study underwent staged PCI procedures and were fully revascularised. This is of key importance taking into consideration the debate on the justification of complete revascularisation in STEMI. The latest publications have shown that patients who underwent complete coronary revascularisation in the acute phase of STEMI have a better prognosis than the others [16, 17]. These studies raise controversies, mainly due to the fact that the results are inconsistent with the results of large trials and meta-analyses [18–21]. Newly presented and vastly discussed trials seem to only support the justification of complete revascularisation in patients with myocardial infarction regarding the aspect of the improvement of the prognosis. However, they do not report the optimal time of complete revascularisation. Undoubtedly, we will be provided with more information from large randomised ongoing trials, e.g. the COMPLETE study. In the presented study, staged revascularisation was performed during a period of 1 month in all the subjects. Consequently, it should not affect the differences in mortality between the groups. Regardless of such treatment, the prognosis of patients with Cx stenosis was worse. Poor outcomes of the Cx group of patients may finally result from missing ECG changes at the time of Cx reocclusion during the observation. This suggests that the 12-lead ECG alone is often not enough for the diagnosis of patients with suspected Cx occlusion or narrowing. According to the authors, this may stem from the fact that electrocardiographically asymptomatic Cx reocclusion during the follow-up could be more common than in the case of RCA. The issue refers to long-term follow-up and not only to the anterior infarction-related period. This may result from atherosclerosis progression, acceleration of the narrowing in already diseased vessels and finally myocardial ischaemia. Additionally, it may be caused by acute occlusion related to the atherosclerotic plaque rupture in that artery. However, these are only unconfirmed assumptions. Therefore, we should be aware of features of Cx occlusion other than ST-segment elevation, such as isolated ST-segment depression in precordial leads (the greatest in leads V2 and V3) [22]. According to our findings, patients with anterior STEMI and Cx stenosis represent a group that requires a thorough evaluation during the follow-up period. Cx is a coronary artery requiring special attention because its stenosis in patients with anterior STEMI treated with PCI of the LAD leads to a worse prognosis in comparison with patients with RCA narrowing.

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What are the different coronary arteries?

The 2 main coronary arteries are the left main and right coronary arteries.

  • Left main coronary artery (LMCA). The left main coronary artery supplies blood to the left side of the heart muscle (the left ventricle and left atrium). The left main coronary artery divides into branches:
    • The left anterior descending artery branches off the left coronary artery and supplies blood to the front of the left side of the heart.
    • The circumflex artery branches off the left coronary artery and encircles the heart muscle. This artery supplies blood to the lateral side and back of the heart.
  • Right coronary artery (RCA). The right coronary artery supplies blood to the right ventricle, the right atrium, and the SA (sinoatrial) and AV (atrioventricular) nodes, which regulate the heart rhythm. The right coronary artery divides into smaller branches, including the right posterior descending artery and the acute marginal artery.
  • Additional smaller branches of the coronary arteries include the obtuse marginal (OM), septal perforator (SP), and diagonals.

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    What Happens If The Circumflex Artery Is Blocked


    How important is circumflex artery?

    The circumflex artery branches off the left coronary artery and encircles the heart muscle. This artery supplies blood to the outer side and back of the heart.

    Is the circumflex artery The Widowmaker?

    A widowmaker heart attack occurs when the left anterior descending (LAD) artery, which supplies blood to the larger, front part of the heart, is blocked at its origin. “This artery delivers a major amount of blood to your heart,” Dr. Rampersad explains.

    Which artery is the most common to have blockage?

    When this happens, patients may go into cardiac arrest. Statistically, Niess said widow-makers are more likely to lead to brain injury and irregular heartbeat. Although blockages can occur in other arteries leading to the heart, the LAD artery is where most blockages occur.

    Is the circumflex artery a main artery?

    The circumflex artery (Cx) is one of the two major coronary arteries that arise from the bifurcation of the left main coronary artery (the other branch being the left anterior descending (LAD) artery).

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