What does a global longitudinal peak systolic strain of –15% indicate and how should it be managed?

A Global Longitudinal Strain of –15% Indicates Reduced Left Ventricular Systolic Function and Warrants Further Cardiac Evaluation and Risk Stratification

A GLS value of –15% falls below the normal threshold and signals impaired myocardial function, even when ejection fraction appears preserved, requiring comprehensive assessment for underlying cardiac pathology and consideration of cardioprotective therapy.

Understanding the Significance

Your GLS of –15% is abnormal. Multiple guidelines establish that:

• Normal GLS ranges from –16% to –22% in most populations 1, 2
• Values worse than –16% (i.e., less negative, closer to zero) raise concern for myocardial pathology 2
• Values <–16% indicate mild depression of GLS, while values <–10% represent severe reduction 1

The 2020 JACC Cardiovascular Imaging consensus specifically states that GLS worse than –16% should raise concern for myocardial pathology 2. Your value of –15% crosses this threshold.

Clinical Implications by Context

If You Have Cardiovascular Risk Factors or Known Heart Disease

GLS is detecting subclinical left ventricular dysfunction before ejection fraction becomes abnormal. This is particularly important because:

• GLS identifies myocardial dysfunction earlier than ejection fraction 3, 4
• It detects subendocardial fiber dysfunction that precedes global systolic failure
• A 10-15% reduction in GLS during therapy predicts subsequent cardiotoxicity 4

If You're Being Evaluated for Coronary Artery Disease

Your GLS of –15% suggests significant coronary disease:

• The optimal cutoff for detecting significant CAD is –16.5% (87.6% sensitivity, 85.7% specificity) 5
• Your value of –15% falls below this threshold
• GLS correlates with the number of diseased vessels and extent of coronary disease 6, 5, 7
• Values between –16% and –10% indicate moderate impairment 1

If You Have Heart Failure with Preserved Ejection Fraction (HFpEF)

GLS <–16% in HFpEF patients demonstrates underlying impaired LV systolic function despite normal ejection fraction 8. This finding:

• Indicates true myocardial dysfunction, not just diastolic abnormalities
• Predicts worse functional capacity and outcomes
• Suggests need for aggressive medical management

If You're an Athlete or Post-COVID

Normal GLS in athletes ranges from –16% to –22% 2. Your value of –15%:

• Falls outside the athletic range
• Should prompt evaluation for occult myocardial involvement 2
• Requires ruling out myocarditis, especially in post-COVID scenarios
• Mandates further testing before return to competitive sports

Management Algorithm

Immediate Steps

1. Review image quality and ensure accurate tracking - GLS is technique-dependent 2

2. Integrate with other echocardiographic parameters:

   • Ejection fraction (should be >52% men, >54% women) 9
   • Diastolic function parameters (E/e', tissue Doppler velocities)
   • Regional wall motion abnormalities 2
   • Left atrial function and size

3. Obtain biomarkers:

   • NT-proBNP ≥125 pg/mL or BNP ≥35 pg/mL suggests cardiac dysfunction 10
   • Troponin if acute process suspected 4, 10

Risk Stratification

Your GLS of –15% places you in an intermediate-risk category:

• Not severe dysfunction (which would be <–10%) 1
• But clearly abnormal (worse than –16% threshold) 2
• Requires investigation for underlying cause

Diagnostic Workup

Based on clinical context:

For suspected coronary disease:

• Proceed with stress testing or coronary angiography 6, 5, 7
• Your GLS suggests high probability of significant stenosis

For heart failure evaluation:

• Complete diastolic function assessment 1, 8
• Consider cardiac MRI if infiltrative disease suspected 9
• Evaluate for HFpEF using comprehensive criteria 8, 10

For cardiotoxicity monitoring:

• A reduction >15% from baseline is very likely abnormal 9
• Consider interruption or modification of cardiotoxic therapy 10
• Initiate cardioprotective medications (ACE inhibitors/ARBs, beta-blockers) 10

Therapeutic Considerations

If reduced GLS is confirmed and persistent:

1. Initiate guideline-directed medical therapy:

   • ACE inhibitors or ARBs 10
   • Beta-blockers 10
   • Consider these even with preserved ejection fraction 10

2. Address underlying causes:

   • Optimize blood pressure control
   • Manage diabetes aggressively
   • Treat coronary disease if present
   • Discontinue or modify cardiotoxic agents if applicable

3. Serial monitoring:

   • Repeat GLS in 3-6 months to assess trajectory
   • Monitor for development of symptoms or EF decline
   • Track biomarkers (natriuretic peptides)

Critical Pitfalls to Avoid

• Don't dismiss abnormal GLS just because ejection fraction is normal - GLS detects dysfunction earlier 3, 4
• Don't rely on GLS alone - integrate with clinical context, symptoms, other echo parameters, and biomarkers 3, 2
• Don't ignore vendor differences - reference ranges may vary slightly by equipment 3
• Don't overlook image quality - poor tracking invalidates results 2
• Don't delay evaluation in high-risk patients - GLS <–15% in certain contexts (post-chemotherapy, acute coronary syndrome) demands urgent assessment 4, 7

Prognostic Significance

GLS ≥–15% (less negative than –15%) is associated with:

• Increased risk of major adverse cardiac events 11, 12
• Higher rates of heart failure hospitalization 8
• Worse outcomes in multiple cardiac conditions 12, 13
• In hypertrophic cardiomyopathy specifically, GLS >–10% carries 4 times the risk of adverse events 12

Your value sits at the threshold where outcomes begin to diverge significantly from normal, making intervention and close monitoring essential.