Cardiovascular diseases Introduction and Types
Diseases related to heart and blood vessels are called cardio vascular diseases, globally cardio vascular diseases are the number one cause of death, more people die from CVD’s than any other disease.
According to World Health Organisation (May, 2017)
Globally 17.7 million people died from cardio vascular diseases in 2015, representing 31% of all global deaths. Of these deaths an estimated 7.4 million were due to coronary artery heart disease and 6.7 million were due to stroke
Over three quarters of cardiovascular diseases take place in the low and middle-income countries.
Types of Diseases
heart is an organ responsible for pumping blood through the system of blood vessels, this system is called the circulatory system, vessels are elastic tubes that carry blood to every part of the body.
Several typed of cardio vascular diseases are there, which can be segregated as
Vascular diseases – diseases involving the blood vessels
1. Coronary Artery Diseases (also called coronary heart disease)- Diseases related to Atherosclerosis, a condition wherein a plaque builds up in the wall of arteries, the plaque is hard on outside and soft on inside, if the shell-like area crack opens the platelets form large clots effectively blocking blood flow, causing heart attack.
Out of the 17.7 million deaths from the cardio vascular diseases in 2015, around 7.4 million Were due to Coronary artery disease.
2. Cerebrovascular disease (eg. Stroke) – Disease affecting the blood supply to the brain,
o Ischemic Stroke – blood vessel that feeds the brain gets blocked, usually due to blood clot, when the blood supply to a part of brain is shut off, brain cells will die, result will be inability to carry out some of the previous functions like walking or talking.
Around 85% of the strokes which occur are Ischemic strokes.
o Haemorrhagic stroke – Blood vessels within the brain leaks or ruptures, most likely cause is uncontrolled hypertension
Diseases involving the heart
1. Cardiomyopathy – A Disease of heart muscles, which causes heart muscles to become thick or rigid, over a period of time heart becomes weaker and unable to pump blood through the body.
This can lead to a heart failure or irregular heartbeat.
2. Hypertensive heart diseases – Diseases due to high blood pressure, that affect the heart.
Coronary Heart Diseases
As Coronary Heart Diseases are responsible for the majority of deaths, we see a huge opportunity in developing an IT solution to address the needs of coronary artery disease patients.
According to Centres for disease control and prevention (CDC)
Coronary Heart Disease(CHD) is the most common type of heart disease, killing over 370,000 people annually²
We will be focussing on coronary heart disease throughout our report, we feel that we have a very strong and evolved market, in terms of the large number of patients suffering from coronary heart diseases.
Coronary Heart Diseases – Risk factors are the conditions or habits that raise risk of coronary heart disease and heart attack.
Controllable risk factors – we can control the risks and their impact on the disease
High Blood Cholesterol – High Blood Cholesterol is a condition in which you have too much cholesterol in your blood, cholesterol is a waxy fat like substance which is found in all cells of the body. When there is too much cholesterol in the blood it builds up in the arteries and increases the risk of developing Coronary Heart diseases
High Blood Pressure – Force of blood pushing against the walls of arteries as the heart pumps blood. High Blood pressure is the Common lifestyle disease, in which blood flows through blood vessels, at higher than normal pressure.
Diabetes – Disease which occurs when your blood glucose, also called blood sugar is too high
Overweight and Obesity – caused by increase in the size and amount of fat cells in the body, apart from being a risk factor for Coronary heart disease, obesity can lead to other risk factors like high blood pressure and high diabetes.
Smoking – Smoking harms nearly every organ of the body, including heart, blood vessels, lungs, eye, mouth, chemicals in tobacco smoke harm your blood cells, they can damage the function of heart and structure and function of your blood vessel.
Lack of physical activity
Non-controllable Risk Factors
Several risk factors which can’t be controlled are
Age- simply getting older increases your risk of damaged and blocked arteries
Gender-Men are generally at greater risk of coronary heart disease, however risk for women increases after menopause.
family history- family history of heart diseases is associated with a higher risk of coronary artery diseases, especially if a close relative develops disease, at an early age.
Stages of the disease
Coronary artery disease, goes through the below mentioned stages
1.Inner lining of a normal coronary artery is smooth and free of any blockages or obstructions
2. As we grow older, lipids or fatty substances (Cholesterols and triglycerides) are deposited as fatty streaks, the streaks are only minimally raised, hence do not produce any obstruction to the flow of blood
3.Patients with one or more risk factors, for coronary artery disease, are susceptible to the increase build-up of fatty layers, known as atheroma, this material begins to encroach upon inner channel and starts to interfere with free flow of blood, deposit of atheroma within the inner lining of arteries is called atherosclerosis.
4.As atherosclerosis progresses fibre begin to grow into and around fatty layers of atheroma, causing the blockage to harden and turn into a plaque, when the channel is reduced by more than 50%, the artery may become obstructed enough to decrease blood flow to heart muscles during time of increased need (exercise, emotional stress)
5. imbalance between the supply and demand can cause chest discomfort (angina), when coronary artery blockage is severe enough to completely cut off the supply of oxygen and nutrients to heart muscles a heart attack can result.
We can go through the stages of the disease with the help of a picture, as given on the site of centres for disease control and prevention (CDC),
As we can see in the image the plaque progressively builds up in the arteries of a person with heart disease, gradually the inside of arteries begin to narrow, which lessens or blocks the flow of blood, plaques can also rupture, in case they are ruptured a blood clot can form on the plaque blocking the flow of blood.
Sign and symptoms of Coronary Artery Disease
Angina – Chest pain or discomfort that occurs if an area of your heart muscle doesn’t get enough oxygen rich blood, angina may feel like pressure or squeezing in chest
Shortness of breath – In case Coronary Artery disease causes heart failure, in which case the heart cannot pump enough blood to meet the body’s needs, fluid build up in lungs makes it hard to breathe.
Some patients who have Coronary Heart disease have no sign or symptoms, condition called silent CHD, so a disease might not be diagnosed until a person has signs or symptoms of heart attack, heart failure, or an arrhythmia
Treatment, New Devices and Technology to treat the disease
Apart from the lifestyle changes to control the risk factors for the coronary artery diseases, several treatment procedures to treat coronary artery diseases are
1.Angioplasty – treatment does not involve a surgery, doctor threads a small tube, called
catheter, through a groin or arm, this device travels through the artery to the site of the blockage, the catheter has a small balloon located on the tip which is slowly inflated to open the blockage.
Post placing the catheter, patients also go through the process of placing the stent, stents are devices which look similar to spring in a ball point pen, once angioplasty has opened the artery, the stent is placed, and expanded to fit the size of the artery, the stent then remains in the artery to keep the blood flow flowing freely in the artery, over time artery wall heals around the stent.
Possible complications after Angioplasty and stent placement
After the artery is narrowed with the help of angioplasty and stent placement, there is a possibility of the gradual re-narrowing of coronary artery, this is called restenosis, if restenosis happens, it usually occurs within 3-12 months of the procedure.
Stents initially were developed to reduce the possibility of restenosis which stents did achieve to an extent, as before the stent placement the occurrences of restenosis were about 40-50% which were reduced to 20-30% after the stent development, over a period of time drug- eluting stents were developed, where in the stents were coated with drugs that inhibit the tissue growth leading to restenosis
A dreaded complication involving occlusion of the stent due to the formation of a blood clot, unlike restenosis, thrombosis can be more deadly as it leads to the sudden complete blockage of the coronary artery, risk of thrombosis is highest within the first few weeks or months after the stent placement.
Latest devices to treat the diseases
Fully absorbable stent to treat coronary artery disease (Absorb GT1 Bio resorbable vascular scaffold system(BVS)
As we have discussed the presence of stent inside the artery could lead to several complications for the patients, the Absorb GT1 Bio resorbable vascular scaffold system(BVS) is latest type of stent was approved by US FDA, in July 2016, this stent releases a drug called everolimus, to limit the growth of scar tissues, thi stent is gradually absorbed by the body approximately within 3 years.
This stent is manufactured from a biodegradable polymer called poly (L- lactide), once the stent is absorbed by the body, there are only 4 small platinum markers embedded in the walls of the artery, which will help the cardiologists identify, where absorb GT1 BVS was placed initially.
absorb GT1 BVS, is manufactured by Abbott Vascular in Santa Clara, California