Microvascular Angina

Question 1

Angina Pectoris - Definition (3)

Answer 1

traditionally defined as central chest
discomfort (pain or tightness) of less than 10 minutes’ duration.

This discomfort is provoked by exertion or emotional stress and is relieved by rest or by administration of nitroglycerin.

In this typical form, angina is suggestive of obstructive coronary artery disease

Question 2

angina pectoris synonymous
w/ obstructive atherosclerotic epicardial
CAD (2)

Answer 2

The main cause for myocardial ischaemia
in clinical practice is considered to be
obstructive CAD

Current diagnostic and therapeutic
strategies for angina are based on this
paradigm

Question 3

The Angina Universe

Question 4

The “classical” approach:
Focus on the atherosclerotic plaque

Question 5

ANGINA PECTORIS: THE PARADIGM

Answer 5

Myocardial ischemia results from a
mismatch between myocardial oxygen
demand and coronary blood flow (supply
limited by coronary atherosclerosis)

Question 6

The Dogma

Answer 6

Patients and physicians frequently view
coronary artery stenosis as a mechanical
problem that can be “fixed” by mechanical means

Question 7

management of IHD (3)

Answer 7

based on the paradigm that myocardial ischaemia is almost always caused by atheromatous CAD

CAD in the absence of myocardial ischaemia = false negative

Ischaemia in the absence of CAD = false positive

Question 8

OVERUSE OF
PCI ORBITA study:

Answer 8

PCI=Placebo in
stable angina

Question 9

Changes in
Angina Management

Question 10

Optical Medical treatments - trials (4)

Answer 10

• Courage
• Orbita
• Ischemia
• ESC Guidelines 2019

Question 11

Microvascular Angina
definition

Answer 11

Markedly increased resistance to coronary blood flow at the site of the coronary microvasculature can trigger myocardial ischaemia, as shown by ECG shifts, myocardial perfusion defects and LV dysfunction in patients who otherwise have patent epicardial coronary arteries

Question 12

Microvascular Angina (Cardiac Syndrome X) (4)

Answer 12

Typical exertional/rest chest pain*
Transient ischaemic ECG changes
Normal coronaries

More prevalent in women in most series; >50% have
documented myocardial ischaemia and >50% coronary
microvascular endothelial dysfunction leading to abnormal MV
dilatation and ischaemia

Question 13

CPNCA: A REAL &
Common Condition

Answer 13

398,978 patients
with suspected CAD
Age, 61 years,
53% men,
26% with diabetes,
70% hypertensive,
Non-invasive testing
in 84% (69% +ve)
60% had coronary
stenoses <50%

Question 14

Prevalence of Coronary Microvascular Dysfunction Among Patients With Chest Pain and Nonobstructive Coronary Artery Disease

Question 15

Functional Causes of Microvascular Angina

Answer 15

Impaired coronary microvascular dilatation reduces CFR and
causes exertional angina. Microvascular spasm can cause rest
angina

Endothelial dysfunction: Conventional risk factors for CAD, Oestrogen deficiency

Chronic Inflammation i.e. RA / SLE, dyslipidaemia

Question 16

Diagnostic Criteria for Microvascular Angina - COVADIS (4)

Answer 16

Signs/symptoms of angina

Absence of obstructive CAD*

Objective evidence of myocardial ischaemia

Coronary microvascular dysfunction (CFR <2.5/MV spasm)

Question 17

Stable angina (5)

Answer 17

High Prevalence of Angina/Myocardial Ischaemia that is not caused by obstructive CAD

 No CAD -No CAD - “Primary MVA”“Primary MVA” (“Cardiac Syndrome X”)

Systemic hypertension, dyslipidaemia, smoking, diabetes, oestrogen deficiency

Cardiomyopathies, LVH, amyloid disease, AS

SLE and Rheumatoid Arthritis

 CAD patients and post-revascularization angina

Question 18

ACS (2)

Answer 18

– MINOCA, Takotsubo syndrome, no reflow

Coronary Microvascular Dysfunction (CMD)

Question 19

1/3 patients undergoing successful PCI has recurrent angina and
a positive ECG exercise test one month after complete and successful PCI

Answer 19

graphs

Question 20

Ach high response in stable angina + unobstructed coronary arteries test (3)

Answer 20

124 (86%) of the patients with NCA underwent i.c. ACH
testing.

Main findings: ~ 50% of patients undergoing diagnostic angiography for stable angina had NCA
and
the ACH test
triggered epicardial or microvascular spasm in > 60 %

Question 21

Myocardial Ischaemia Triggered by Coronary Microvascular Spasm

Answer 21

In patients with Ach induced epicardial or microvascular spasm ECG shifts and chest pain were associated with reversible ischemic
changes on SPECT and Echo, and increased high sensitivity cTn

Question 22

Data from the WISE
project - women

Answer 22

The presence of
coronary microvascular
dysfunction is
associated with
impaired cardiac
outcomes in women, contrary to initial
views

Question 23

The Need to Identify Ischemia In Patients INOCA (5)

Answer 23

 Poor quality of life

 MACE, 2.5% annual rate

 10% have prior subclinical MI which predicts MACE

 Healthcare spending similar to that in obstructive CAD

 Patients receive
inappropriate treatment

Question 24

Microvascular angina in the angina universe

Question 25

INOCA- The Rationale for Adjunctive
Testing of Coronary Vascular Function (3)

Answer 25

1. A normal angiogram does not exclude ischaemia caused by coronary vascular dysfunction. Hence angiography is an “incomplete” study
   without adjunctive diagnostic tests of coronary vascular function
2. Functional testing in INOCA patients allows the cardiologist to make the correct diagnosis, offer therapy that can improve QOL and gather prognostic information
3. Functional testing providing a diagnosis also “empowers the patient who is often in limbo regarding the cause of their symptoms”

Question 26

What is the effective management of angina based on?

Answer 26

largely dependent on
efficiently targeting the prevailing pathogenic mechanism

Question 27

Stable angina treatment pre-referral for revascularisation (6)

Answer 27

Identify the prevailing
pathogenic mechanism

Tailor treatments to individual needs

 Improve endothelial function (Risk
factors, statins, exercise, ACEI, Oestrogen)

 Angina/Ischaemia – CCB and BB useful in
effort-induced MVA and vasodilators (nitrates, nicorandil, CCB) for
microvascular spasm

 Tackle cardiometabolic issues
(Metformin, ranolazine and trimetazidine)

 Pain management (Imipramine,
aminophylline, TENS, SCS)

Question 28

Primary Microvascular Angina: Treatment Targets

Answer 28

Increased MVO2 demand
(High BP- Tachycardia) : BB, CCBs, Ivabradine

Coronary artery spasm: Nitrates, CCBs, Nicorandil, Rho-K I

Impaired coronary microvascular
dilatation -Nitrates - CCBs, Nicorandil, HRT

Heart metabolic abnormalities

Effects of ischaemia per se
(microvascular compression) : Ranolazine, Metformin, Trimetazine

Inflammation: statins, colchicine (biologicals?)

Question 29

Summary (5)

Answer 29

 The current paradigm (“plaque-centred”) is flawed. A mechanistic, ischaemia-centred- working hypothesis is
required

 Prevalence of CMD and microvascular spasm is higher
than originally thought

 MVA may affect ~50% of patients undergoing
diagnostic angiography

 CMD is both a risk factor and a target for treatment

 MVA patients need to be identified and treated rationally