Treatment for lung cancer in patients with heart disease

As a risk factor, smoking is common to both atherosclerosis and lung disease and, as a result, a disproportionately large number of patients with atherosclerosis also present with interstitial lung disease and lung cancer (bronchogenic carcinoma). It is not at all uncommon, therefore, for lung cancers to be detected during investigations prior to cardiac surgery. If heart surgery has been scheduled anyway, it may be possible to arrange for the lung cancer to be removed at the same time. The decision as to whether it is feasible or even advisable for such surgical procedures to be combined must be made on a case-by-case basis. For optimal therapy planning, cardiothoracic surgeons, cardiologists and anesthetists work together as part of an interdisciplinary team.

Close cooperation of specialist cardiac and thoracic surgeons is also necessary in cases where the patient does not have heart disease, but their lung cancer is located very close to the heart and its surrounding structures, making the removal of the cancer impossible without concurrent surgical repair on the heart. Naturally, this type of procedure also requires close interdisciplinary cooperation throughout the preoperative stage.

In addition to surgery, lung cancer treatment usually also involves radiation therapy and chemotherapy. Given the effects of this type of treatment, a patient undergoing heart surgery may face the prospect of significantly impaired immune function and significantly impaired wound healing. Cancer treatment, therefore, always has to be timed in such a way as to avoid interfering with necessary surgical procedures. In many cases, it may be advisable to treat the heart condition prior to treating the lung cancer.

Lung cancers usually develop slowly, over a number of years. In contrast to heart disease, it is therefore rare for lung cancers to suddenly turn into medical emergencies. As a result, a patient whose heart condition requires treatment should first undergo whatever surgical or non-surgical treatment is required. Afterwards, the patient's physicians will be in a position to choose whatever lung cancer treatment they consider necessary. The commonly held belief that cancer treatment must be started as soon as possible, and cannot be delayed by a day, a week or even several weeks, does not in fact apply in most lung cancers, and the start of treatment may even be postponed until after the patient has been discharged and undergone cardiac rehabilitation.

What is pulmonary embolism?

A pulmonary embolism is a sudden blockage in a pulmonary artery, caused by what is referred to as an embolus, and usually consists of a blood clot that has travelled from the veins in the legs or pelvis. An embolism occurs when a blood clot (thrombus) breaks off from its site of origin and travels in the bloodstream to the lungs, where it can cause major blockages. By reducing the ability of the heart to pump blood around the body, this reduces both the amount of oxygen reaching the rest of the body, as well as the amount of carbon dioxide being removed.

While a small pulmonary embolism, i.e. a blockage affecting a small vessel in the lungs, may go completely unnoticed, a blockage in a major pulmonary artery can be life-threatening and constitutes a medical emergency. The majority of such emergencies can be treated with medicines to dissolve the blood clot (thrombolysis), Some, however, require surgical treatment to remove the blood clot (Trendelenburg procedure), which is performed using a cardiopulmonary bypass machine, also known as a heart-lung machine. In rare cases, a pulmonary embolism may also be caused by air bubbles, fat droplets or amniotic fluid.

Pulmonary embolism can be chronic. This can occur when minor blood clots from elsewhere in the body slowly build up inside the vessels of the lungs, causing them to become increasingly blocked. Once the deposits inside the veins harden, thrombolytic drugs become ineffective. In certain cases, it may be possible to surgically remove these hardened deposits (pulmonary thromboarterectomy, PTE), thus restoring normal blood flow through the lungs. As this is a complex procedure, and associated with certain risks to the patient, the decision as to whether a patient is a suitable candidate must be made on a case by case basis, and must take into account both the risks and benefits associated with the procedure.

What are the main symptoms of pulmonary embolism?

• Breathing difficulty, combined with rapid breathing
• Coughing, which may include coughing up blood
• Chest pain, particularly when breathing in
• Rapid pulse, palpitations
• Restlessness, anxiety
• Sweating
• Blue discoloration (cyanosis) of the lips and fingernails.

What are the possible causes of pulmonary embolism?

Pulmonary embolism is almost always caused by venous thrombosis.
Important risk factors include: 

• Long periods of bed rest, e.g. following surgery
• Excess weight
• Smoking
• Oral contraceptives (contraceptive pill)
• Varicose veins
• Cardiovascular diseases such as atrial fibrillation
• Certain cancers
• An inherited predisposition to thrombosis

Diagnosis of pulmonary embolism

• Chest x-ray
• ECG and blood tests
• Cardiac ultrasound scan (echocardiogram)
• Visualization of the blood vessels in the lungs (angiography) using different techniques, in particular color-coded CT scans

Treatment of pulmonary embolism

Treatment selection is dependent upon the severity of the disease.

Rest, oxygen and medication

General measures, which also apply in cases of minor embolism, include bed rest, as well as the administration of oxygen and anticoagulant medication. Anticoagulant treatment is continued for some time after symptoms have resolved, in order to prevent further blood clots from forming.

Thrombolytic therapy

Treatment for severe cases of pulmonary embolism also includes intravenous drip administration of special drugs, in order to dissolve the blood clots inside the pulmonary artery (thrombolytic therapy).

Catheter-based procedures

In some cases, physicians will perform a catheter-based procedure: after insertion through a blood vessel in the groin, a cardiac catheter is advanced to the blocked pulmonary vessel, where it is used to break up the blood clot (catheter-based clot fragmentation).

Surgery

In rare cases, cardiovascular surgery may be required to remove the blood clot. Patients with chronic pulmonary embolism as a result of recurrent small embolisms may also benefit from surgery. As this type of surgery is complex, the risks associated with it must be taken into account, and weighed against any potential benefits.