Research · DrNB (Cardiology) dissertation · 2024
Finding the diabetic heart in trouble while the ejection fraction still looks normal
Analysis of Myocardial Work by Non-invasive Left Ventricular Pressure-Strain Loop in Patients With Type 2 Diabetes Mellitus
DrNB (Cardiology) · P. D. Hinduja National Hospital and Medical Research Centre, Mumbai · National Board of Examinations in Medical Sciences (NBEMS), New Delhi
Under the guidance of Dr Sudhir Pillai, Consultant Cardiologist
120
Participants
60
With type 2 diabetes
60
Matched controls
10.0%
Mean HbA1c in diabetes
Single-centre case-control study, age- and sex-matched · 2021–2024 · Tertiary care hospital, Mumbai · 2D echocardiography, Speckle-tracking echocardiography, Non-invasive LV pressure-strain loop, GE Vivid E95
The problem
Ejection fraction — the number almost every echo report leads with — stays normal until diabetic heart disease is already well advanced. By the time it falls, muscle has been lost. The question is whether something measurable goes wrong earlier.
The question
What I set out to answer
In people with type 2 diabetes whose ejection fraction still reads normal, can myocardial work measured from a non-invasive pressure-strain loop detect heart muscle dysfunction that conventional echocardiography would call unremarkable?
- Evaluate myocardial work parameters in patients with type 2 diabetes mellitus.
- Compare myocardial work indices with age- and gender-matched healthy controls.
- Assess myocardial function using non-invasive LV pressure-strain loop technology.
- Determine the relationship between glycaemic control and myocardial work.
The findings
What the study showed
Every parameter below is shown as it was measured — both group averages, the spread around them, and the p-value.
Myocardial work — the pressure-strain loop indices
Ordered by how far apart the two groups actually sat, not by how small the p-value was. GLS is a negative number, so a value closer to zero is worse.
Global wasted work(mmHg%)
The only index that rises in diabetes — wasted work is effort the muscle spends without moving blood.
Global work efficiency(%)
Global longitudinal strain(%)
Global constructive work(mmHg%)
Global work index(mmHg%)
What a conventional echo showed
The comparison that matters for interpreting the study honestly — see the note beneath.
Ejection fraction(%)
Lower in diabetes, but both group averages sit comfortably inside the normal range — which is exactly the problem the study is about.
E/e′ (filling pressure)
Left atrial diameter(mm)
LV posterior wall thickness(mm)
Who the two groups were
Age and sex were matched by design; the groups differed where you would expect diabetes to make them differ.
HbA1c(%)
Fasting plasma glucose(mg/dL)
Age(years)
Body mass index(kg/m²)
Worth reading carefully: the conventional filling-pressure measure E/e′ separated the two groups as strongly as any myocardial work index did. So the honest claim is not that pressure-strain loop imaging sees what ordinary echocardiography cannot — it is that the heart muscle is measurably abnormal while the ejection fraction, the number most reports lead with, still reads normal.
Could the measurements be repeated?
Agreement between two readers, and between repeat readings by the same reader (intraclass correlation — 1.00 is perfect).
The conclusions
What it means
In people with type 2 diabetes, the heart muscle is already working measurably worse while the ejection fraction still reads as normal.
Wasted work rose and work efficiency fell — the diabetic heart spent more effort to deliver less of it.
Global longitudinal strain and the myocardial work indices moved together, each describing a different part of the same problem.
The measurements proved highly reproducible between observers and on repeat reading, which matters if a technique is ever to be used clinically.
Why it matters at the bedside
If you have type 2 diabetes and your echo report says the pumping function is normal, that is genuinely good news — but it is not the whole picture. Strain and myocardial work can show strain on the muscle years before the ejection fraction moves, and that is the window in which tightening blood pressure, glucose and lipid control still changes the story.
What this study could not answer
- A small, single-centre cohort — a larger multi-centre study is needed before these numbers can be treated as representative.
- Speckle-tracking has a technical ceiling: if the speckles move out of the imaging plane during contraction, the software cannot track them.
- Cross-sectional by design — nobody was followed up, so the study cannot say whether these changes go on to cause heart failure, or whether treating them changes anything.
- Glycaemic control did not correlate meaningfully with myocardial work in this cohort (r = −0.118), so no claim is made about HbA1c driving these findings.
From that ward to this cath lab
This is the work that shaped how I read an echocardiogram. A normal ejection fraction is a reassuring sentence in a report, not a clean bill of health — and knowing where else to look is most of the job in a diabetic patient who has started to feel breathless.
Questions about the evidence behind your treatment?
Bring your reports — and your scepticism. Both are welcome at the consultation.