Heart Attack

Medical definition1-8

  • Heart attack is a serious manifestation or expression of Coronary Heart Disease.
  • Heart attack occurs when blood flow to a part of the heart muscle is blocked for a certain period of time leading to heart muscle damage.
  • A heart attack occurs when a blocked artery prevents oxygen-rich blood from reaching a section of the heart.
  • If the blocked artery is not reopened quickly, the part of the heart normally nourished by that artery begins to die.
  • The longer a person goes without treatment, the greater will be the damage.
  • The coronary arteries supply oxygen and nutrient-rich blood to the heart, and hence a blockage (or blood clot) in these arteries can cause heart attack.
  • Heart attack is also known as Myocardial Infarction (MI) because it occurs when a coronary artery suddenly becomes at least partially blocked by a blood clot, causing a part of the heart muscle (myocardium) being supplied by that artery to become infarcted (that is, to die).

Golden Hour & its importance9-11

  • A heart attack occurs when a narrowing in the arteries and /or a sudden blockage from a blood clot cuts off the nutrients and oxygen supply to the heart muscle.
  • The heart muscle starts to die within 80-90 minutes after it stops getting blood supply, and this critical time is termed as the ‘Golden Hour’. Because immediate action is so critical to limit heart muscle (myocardial) damage & optimize a better recovery for the patient, health care professionals refer to this time frame as ‘The Golden Hour’.
  • Golden hour is the critical one hour from the onset of a heart attack. Most of the heart attack deaths occur during this period if not treated properly.
  • Within six hours, after an impeded blood supply almost all the affected parts of the heart could be irreversibly damaged, if not promptly treated.
  • The Golden Hour is a window of opportunity that impacts a patient's survival and quality of life following a heart attack.
  • A systematic review of studies in Indians with CAD from Jan 1969 to Oct 2012 revealed that the median time taken by the patient to reach a hospital after a heart attack (MI) was 360 min9.

Heart attack (MI) classification

  • The ECG is an integral part of the diagnostic work-up of patients with suspected heart attack (MI) and should be acquired and interpreted promptly (i.e. target within 10 min) after clinical presentation.
  • The degree of blood vessel (coronary arterial) blockage caused by the blood clot (thrombus) determines the amount of myocardial damage that occurs and the type of acute coronary syndrome that results.
  • For the sake of immediate treatment strategies, such as reperfusion therapy, it is usual practice to designate MI in patients with chest discomfort, or other ischemic symptoms that develop ST elevation in two contiguous leads as an ‘ST elevation MI’ (STEMI). In contrast, patients without ST elevation at presentation are usually designated as having a ‘non ST elevation MI’ (NSTEMI). Many patients with MI develop Q waves (Q wave MI), but others do not (non Q MI). Patients without elevated biomarker values can be diagnosed as having unstable angina.
  • In addition to these categories, MI is classified into various types, based on pathological, clinical and prognostic differences, along with different treatment strategies. The Universal classification of MI includes-
    • Type 1: spontaneous myocardial infarction
    • Type 2: myocardial infarction secondary to an ischemic imbalance
    • Type 3: myocardial infarction resulting in death when biomarker values are unavailable
    • Type 4a: myocardial infarction related to percutaneous coronary intervention
    • Type 4b: myocardial infarction related to stent thrombosis
    • Type 5: myocardial infarction related to coronary artery bypass grafting
STEMI (ST segment elevation Myocardial Infarction)
  • A characteristic elevation in the ‘ST segment’ portion of ECG.
  • ST-segment elevation indicates full thickness injury of heart muscle.
  • The elevated ST segment indicates that a relatively large amount of heart muscle damage (myocardial damage) is occurring (because the coronary artery is totally occluded), and is what gives this type of heart attack its name.
NSTEMI (Non-ST Segment Elevation Myocardial Infarction)
  • It may be defined as a development of heart muscle/myocardial damage without the ECG change of ST-segment elevation, resulting from an acute interruption of blood supply to a part of the heart and can be demonstrated by an elevation of cardiac markers (CK-MB or troponin) in the blood.
  • Absence of ST-segment elevation in NSTEMI is understood to involve less than full thickness (partial thickness) damage of heart muscle.
  • NSTEMI usually occurs by developing a partial occlusion of a major coronary artery or a complete occlusion of a minor coronary artery previously affected by atherosclerosis.
Unstable angina
  • Unstable angina or sometimes referred to as acute coronary syndrome causes unexpected chest pain, and usually occurs while resting.
  • The most common cause is reduced blood flow to the heart muscle because the coronary arteries are narrowed by fatty build-ups (atherosclerosis) which can rupture causing injury to the coronary blood vessel resulting in blood clotting which blocks the flow of blood to the heart muscle.
  • Unstable angina is characterized by partial/intermittent occlusion (blockage) in a coronary artery, with no myocardial damage

Alarming Statistics on heart disease

Heart Disease- Global scenario
  • Cardiovascular disease (CVD) is the leading cause of death worldwide, accounting for 17.5 million deaths in 2012 (of these deaths, an estimated 7.4 million were due to coronary heart disease and 6.7 million were due to stroke ), a number that is expected to grow to more than 23.6 million by 2030.36-38
  • Approximately one-fifth of the global population resides in South Asia (India, Pakistan, Bangladesh, Nepal, and Sri Lanka), where people suffer from a disproportionately high rate of CVD-related morbidity and mortality.39-42
  • Nearly 80% of all cardiovascular-related deaths occur in low & middle income countries, and at a younger age in comparison to high-income countries.43
  • Nearly 2,150 Americans die each day from cardiovascular diseases, one every 40 seconds.
  • About 85.6 million Americans are living with some form of cardiovascular disease or the after-effects of stroke.38
  • About 610,000 people die of heart disease in the United States every year–that’s 1 in every 3 deaths.44-45
  • Every year about 735,000 Americans have a heart attack. Of these, 525,000 are a first heart attack and 210,000 happen in people who have already had a heart attack.46
  • In a large international, case-control study of first heart attack (myocardial infarction or MI), results indicated that the mean age for first MI was significantly lower in South Asian participants (53.0 years) than in participants from other countries (58.8 years). In approximately 10% of these cases, first MI in South Asian participants occurred in those aged 40 or below. These data indicate a growing epidemic of premature CVD in South Asian populations.47
Heart Disease- National scenario
  • Heart disease risk factors including unhealthy lifestyle, obesity, hypertension and dyslipidemia rapidly escalate by the age of 30 to 39 years in Asian Indians.48
  • Asian Indians (living both in India and abroad) have one of the highest rates of heart disease (particularly coronary artery disease or CAD) in the world, three times higher than the rates among Caucasians in the United States. The CAD among Indians is usually more aggressive at the time of presentation compared with whites or East Asians.49
  • According to the World Health Report, heart disease in Indian population occurs 10 to 15 years earlier than in the western population.50
  • Based on 2015 statistics, about 12 percent of those experiencing heart attacks in India are below 40 years of age; double the number as seen in Western population.51
  • Recent (2015) data suggest that in India, there are roughly 30 million heart patients and two lakh heart surgeries are being performed every year.52
  • Of the 30 million heart patients in India, 14 million reside in urban areas and 16 million in rural areas. If the current trend in heart disease numbers continues, by the year 2020, the burden of atherothrombotic cardiovascular diseases in India will surpass that of any other country in the world.52
  • Today, cardiac hospitals in India perform over 2,00,000 open heart surgeries per year, one of the highest, worldwide. There has been a steady annual rise to the tune of 25-30 per cent per year in the number of coronary interventions over the past several years.52
  • According to Dr. Deepak Natarajan, Senior Consultant Cardiologist, Indraprastha Apollo Hospitals, "Annually, nearly 72 lakh people die due to heart attacks worldwide of which nearly 50% cases are from India.53
  • Indian men lead the global list in under-40 heart attacks. The India Today-Saffolalife Study 2011 on 46,000 urban Indians shows that 78 per cent of men between 30 and 34 run the risk of a heart attack. And their hearts are ageing faster than their real age.54
  • Four people die of heart attack every minute in India and the age group is mainly between 30 and 50. Twenty-five per cent of heart attack deaths occur in people less than 40 .
  • Nine hundred people under 30 die due to heart disease in India every day. The statistics in our country may represent only the tip of the iceberg. According to Dr.Kader Sahib, consultant and interventional cardiologist, Apollo Hospital, Tiruchi, due of poor reporting of cases and incomplete collection of statistical data, the actual figures for young Indians suffering from coronary artery disease may be much more than that reported in studies.55
  • A rough calculation shows that 13 people die due to heart attacks every minute worldwide, which is a huge figure. But we lack a proper registry in India to know the exact figure.
  • Lack of awareness about the disease is just adding to the number of deaths. Many people don't even know that they had a heart attack, and by the time they reach a nearby hospital the precious time or golden hour gets lost.
  • A recent survey shows that most heart attack patients reach hospital roughly six hours after the heart attack. This makes doctors' task difficult and diminishes survival chances too. Anil Bansal, chief cardiologist at Gurgaon's Columbia Asia Hospital said ‘over 50 percent of patients suffering from heart attack die just because they are unable to reach the hospital in time’.56
Heart disease- Regional scenario
  • Dr. Ashok, head of neurology at Mumbai's Hinduja Hospital has observed a 15-20 percent increase in strokes in the 25 to 40 age group51. Evidence from a study conducted in a tertiary care centre located in Chandigarh, revealed narrowing of at least one coronary blood vessel in 34% male and 20% female population, additionally 23.6% of these subjects were less than 40 years old.57
  • According to a report from the Registrar General of India the mortality due to CAD is greater in southern India whereas stroke is more common in the East Indian states58.
  • There are large regional differences in cardiovascular mortality in India.
  • The mortality is highest in south Indian states, eastern and north-eastern states and Punjab in both men and women, while mortality is the lowest in the central Indian states of Rajasthan, Uttar Pradesh and Bihar. Sub-analysis of the mortality trends shows that CHD mortality is higher in the south Indian states while stroke mortality is higher in the east Indian states.59
  • Kerala, with a population of over 33 million, is the most advanced state in epidemiological transition and has the highest prevalence of CAD risk factors in India. The overall prevalence of definite CAD was 3.5 % in men and 4.8 % in women 2.6 %. Prevalence of any CAD was 12.5 % in men 9.8 % and women 14.3 %.60
  • Heart attacks and other cardiac-related ailments caused 54% of all deaths in Chennai city in 2015. Doctors have reported an alarming rise in cardiac disease in the city and data from Corporation of Chennai's death registry corroborates this: No less than 88 people died of heart attacks and other cardiac problems every day in Chennai last year. As many as 32,339 people died in Chennai of heart failure in 2015, the registry shows -making it far and away the biggest killer in the city.61

Need of the Hour (addressed by iMMi Life)

Need of the hour is heart safety, and your heart safety is iMMi Life’s pledge!

  • The National Commission on Macro-economics and Health had projected the evolving epidemic of coronary artery disease in India to be 60 million patients with CHD by the year 2015 with a yearly mortality close to 3 million. According to them, a substantial number of this will be due to acute STEMI or the delayed consequences of STEMI.
  • Four people die of heart attack every minute in India and the age group is mainly between 30 and 50. A majority of patients suffering from heart attack die just because they are unable to reach the hospital in time. Lack of awareness about the disease is also adding to the number of deaths.
    • Considering the rising rates of cardiac events that are early-onset, sudden and fatal in our country, an immediate focus on timely diagnosis and appropriate management is of prime importance.
    • Quick diagnosis and cardiologist advice, the prime requisites for a heart attack imminent are iMMi Life’s deliverables for saving a life!
  • India is a country where there are less than 5,000 credentialed cardiac specialists (4,000 cardiologists and 1,200 cardiac surgeons) with as many as 1 million potential cardiac events happening per month.
    • The absence of cardiac support at the neighbourhood hospital contributes in a major way to why a patient might not seek help at the onset of symptoms.
    • There is a need to reduce the time lag between the appearance of symptoms and hospitalization (‘symptom to door’ metric).
    • With the iMMi Life system, a patient is encouraged to visit his/her neighbourhood hospital at the onset of any of the classic 14 heart attack symptoms.
  • When a heart attack strikes, seconds count for everyone, regardless of your gender, age or ethnicity. Any delay in treating your heart attack increases your chances of permanent, irreparable damage to your heart, and, it could cost you your life.
    • As time elapses during a heart attack, a blockage in the coronary arteries starves the heart muscle of the oxygen it needs to function.
    • For the best odds of saving the heart muscle, a heart attack victim must get to the emergency room immediately, in which case doctors will try toreopen the blockage within 90 minutes or less of arrival time at the hospital.
    • You may hear this critical window of time referred to as ‘door-to-balloon’ time because it measures the time from walking through the hospital doors until blood flow is restored to the heart through the use of an angioplasty balloon.
  • iMMi Life’s innovative technology & cardiologists’ network envisions to save lives and improve clinical outcomes in cardiology through easy & early detection of heart attacks.
  • iMMi Life enables heart attack identification by cardiologists remotely through an application. Cardiologists’ opinion on imminent ECG is communicated to the local clinic through iMMi Life, based on which the attending physician can promptly act & stabilize the patient until he is rushed to a tertiary care hospital.
  • Simple technology like ours has the potential for quicker adoption at the primary care level and can vastly improve clinical outcomes at the various levels of management of heart attack, whether it is medical or interventional. Early detection is a key for patients to be worked up for higher level of care.