Comparing Cardiac Genetic Testing Pathways: Impacts on Access, Informed Choice, and Decisional Satisfaction

While integrating genetic testing into cardiology clinics significantly improved patient access and reduced wait times compared to traditional genetics referrals, it resulted in lower rates of informed decision-making, underscoring the critical need for structured education within mainstreamed pathways.

The Gist

Imagine your heart is a complex, high-performance engine. Sometimes, that engine has a hidden flaw written in its blueprint (your DNA). Finding this flaw early can save lives, not just for you, but for your family members who might share the same blueprint. This is what cardiac genetic testing does.

However, for a long time, getting this test was like trying to get a ticket to a sold-out concert through a single, tiny ticket booth. You had to wait in a very long line (months or even years) to see a specialist called a Genetic Counselor before you could even buy a ticket (get tested).

This paper compares two different ways of getting that ticket: the Old Way (waiting in line) and a New Way called "Mainstreaming."

The Two Pathways: A Race Analogy

1. The Old Way: The "Specialist Only" Line

• How it works: Your heart doctor (cardiologist) says, "You need a genetic test." They write a referral, and you have to go to a separate building to see a Genetic Counselor.
• The Experience: You wait in the lobby. Sometimes you wait 3 to 6 months. When you finally get in, the counselor sits down with you, explains everything in detail, and makes sure you understand the risks and benefits before you take the test.
• The Result: You are very well-informed, but you waited a long time.

2. The New Way: "Mainstreaming" (The Express Lane)

• How it works: Your heart doctor says, "You need a genetic test," and they give you the test right there in their office. They act as the gatekeeper, skipping the long line at the Genetic Counselor's office.
• The Experience: You get the test immediately. Your doctor gives you a pamphlet and a quick chat about what the test is.
• The Result: You get tested very fast, but you might not understand the "fine print" as well.

What the Study Found: The Trade-Off

The researchers looked at hundreds of patients with heart conditions (HCM and DCM) to see which way worked better. Here is the breakdown using simple terms:

1. Speed and Access (The "Who Got Tested?" Score)

• Mainstreaming (New Way): 82% of patients actually got tested.
• Old Way (Referral): Only 69% of patients got tested.
• Why? In the Old Way, many people just gave up while waiting in the long line. They forgot, got busy, or lost hope. The New Way was so fast that people actually followed through.
• The Wait Time: In the Old Way, people waited an extra 3 to 6 months just to get an appointment. In the New Way, it was immediate.

2. Understanding (The "Did You Get It?" Score)

• Mainstreaming (New Way): Only 62% of patients truly understood the test, its limitations, and what the results meant.
• Old Way (Referral): 91% of patients understood everything perfectly.
• The Metaphor: Imagine buying a complex piece of furniture.
  • In the Old Way, you spent an hour with an expert who explained how to build it, what could go wrong, and how to fix it. You knew exactly what you were doing.
  • In the New Way, you bought it instantly at a store with a quick receipt. You got the furniture faster, but you didn't know how to assemble it or what to do if a part was missing.

3. Happiness (The "Did You Feel Good About It?" Score)

• Good News: Surprisingly, both groups were very happy with their decision. Even the people who understood less in the New Way felt confident they made the right choice. They trusted their heart doctor.

The Big Problem: The "Negative Result" Trap

The study found one specific thing that confused people in the New Way: What happens if the test is negative?

Many patients thought, "If the test says 'No genetic problem,' then my heart is safe, and my family doesn't need to worry."
This is wrong.

• The Reality: Current technology can't find every genetic glitch. A negative result just means "We didn't find the specific ones we looked for." It doesn't mean the problem doesn't exist.
• The Risk: In the New Way, patients with negative results often left the doctor's office thinking they were "cured" or that their family was safe, when they actually still needed heart screenings. In the Old Way, the Genetic Counselor made sure everyone understood this crucial nuance.

The Verdict: What Should We Do?

The study concludes that we can't just pick one side. We need a Hybrid Model (a mix of both).

• Keep the Speed: Let heart doctors offer the test immediately so people don't drop out of the system due to long waits.
• Add the Safety Net: But, we need to make sure the heart doctors have better "toolkits" (videos, better pamphlets, checklists) to explain the complex stuff.
• The "Traffic Cop" System: If a test comes back positive or confusing, the patient should be immediately sent to a Genetic Counselor (the expert) to explain the results to the family.

In short: The New Way gets people through the door faster, but the Old Way teaches them how to navigate the house. The best solution is to let the heart doctor open the door quickly, but ensure a guide is waiting inside to show everyone the way.

Technical Summary

1. Problem Statement

Cardiac genetic testing is critical for diagnosing cardiomyopathies (Hypertrophic Cardiomyopathy [HCM] and Dilated Cardiomyopathy [DCM]), guiding clinical management, and enabling cascade testing for at-risk family members. However, traditional service delivery models relying on referrals to specialized Medical Genetics clinics face significant bottlenecks:

• Limited Resources: High demand for genetic counseling exceeds the availability of specialized counselors.
• Long Wait Times: Patients face substantial delays before accessing testing, hindering timely diagnosis and family screening.
• Low Uptake: Many patients referred to genetics fail to follow through due to logistical barriers or loss to follow-up.

While "mainstreaming" (shifting pre-test activities to non-genetic clinicians, such as cardiologists) has improved access in oncology, its application in cardiology is less studied. The core tension addressed by this study is whether mainstreaming improves access at the cost of informed decision-making, given that cardiologists lack formal genetic training.

2. Methodology

The study was a real-world implementation study conducted in Alberta, Canada, from September 2024 to September 2025.

• Study Design: A comparative analysis of two pathways for patients diagnosed with HCM or DCM:
  1. Mainstreaming Pathway: Six high-volume cardiac specialists initiated genetic testing directly in outpatient settings without prior referral to genetics. They utilized a provided toolkit (checklists, patient info sheets, FAQs, and a video) to educate patients.
  2. Traditional Pathway (Control): Patients referred to the Edmonton Medical Genetics Clinic, where they attended either a provincial patient webinar followed by a brief phone call, or a one-on-one genetic counseling appointment.
• Participants:
  • Mainstreaming Group: 116 patients offered testing (91 outpatients, 25 inpatients).
  • Traditional Group: 176 patients referred to genetics.
• Data Collection:
  • Administrative Data: Uptake rates (sample collection) and time-to-testing.
  • Patient Surveys: Online surveys administered to outpatients in both groups (excluding hospitalized patients due to stress).
• Key Metrics:
  • Access: Percentage of patients who proceeded to sample collection.
  • Time to Testing: Days from referral/offer to sample collection.
  • Informed Choice: Measured using the Cardiac Multidimensional Model of Informed Choice (MMIC) scale. This required a knowledge score $\ge$75% on 8 true/false questions (covering limitations, inheritance, uncertainty) and an attitude consistent with their testing intention.
  • Satisfaction: Measured using the validated Satisfaction with Decision Scale (6-item, 5-point Likert).

3. Key Contributions

• First Comparative Data in Cardiology: Provides robust empirical evidence comparing mainstreaming vs. traditional genetics pathways specifically for cardiomyopathies, an area previously lacking data compared to oncology.
• Quantification of the Access-Knowledge Trade-off: Explicitly demonstrates the trade-off between rapid access and patient understanding, showing that while mainstreaming increases testing volume, it significantly reduces the rate of "informed choice."
• Identification of Knowledge Gaps: Pinpoints specific concepts (limitations of testing, variable expression, uncertain results) that patients struggle to understand regardless of the pathway, but particularly in mainstreaming.
• Toolkit Evaluation: Evaluates the efficacy of a standardized toolkit (info sheets, videos) in a non-geneticist setting, finding that while helpful, it is insufficient to match the knowledge levels achieved through structured webinars.

4. Key Results

A. Access and Uptake

• Mainstreaming Uptake: 82% (95/116) of patients offered testing proceeded to sample collection.
• Traditional Uptake: 69% (121/176) of referred patients proceeded to sample collection.
• Reason for Difference: The lower uptake in the traditional group was primarily due to patients failing to follow through with referrals (lost to follow-up or declining appointments).
• Wait Times:
  • Mainstreaming: Immediate (0 days).
  • Traditional (Webinar): Median 94 days (IQR 60–201).
  • Traditional (One-on-One): Median 185 days (IQR 118–224).

B. Informed Choice and Knowledge

• Informed Choice Rate:
  • Mainstreaming: 62% (38/61 survey respondents) were classified as "informed."
  • Traditional (Webinar): 91% (110/121 survey respondents) were classified as "informed" ($p < 0.01$).
• Knowledge Scores:
  • Mainstreaming Mean: 77% (SD 20%).
  • Traditional Mean: 89% (SD 13%).
• Specific Challenges: Patients in both groups struggled most with understanding that a negative test does not rule out a genetic cause, the concept of variable expression, and the possibility of uncertain results.
• Impact of Materials: In the mainstreaming group, those who received the patient information sheet had a higher informed choice rate (69%) than those who did not (52%), though the difference was not statistically significant ($p=0.17$).

C. Patient Satisfaction

• Decision Satisfaction: High across both groups with no statistically significant difference.
  • Mainstreaming: 4.41/5.0 (SD 0.84).
  • Traditional: 4.53/5.0 (SD 0.57).
• Experience: Patients in the traditional webinar group reported significantly higher rates of being informed about when and how results would be delivered (95% vs. ~60% in mainstreaming).

5. Significance and Implications

• System Efficiency vs. Quality of Care: Mainstreaming successfully addresses the systemic bottleneck of long wait times and low referral follow-through, significantly increasing the volume of patients receiving genetic testing.
• The "Informed" Deficit: The study concludes that while mainstreaming improves efficiency, it currently compromises the quality of informed decision-making. This is critical in cardiology because genetic results drive cascade testing for family members; if patients do not fully understand the implications (e.g., limitations of testing), they may fail to communicate risks effectively to relatives.
• Recommendations for Implementation:
  • Hybrid Models: A model where cardiologists initiate testing but genetics professionals provide targeted post-test support (especially for positive/uncertain results) is recommended.
  • Enhanced Education: Standardized, high-quality educational resources (videos, decision aids) are necessary but must be rigorously tested. The study suggests patient videos may be non-inferior to in-person counseling for knowledge acquisition.
  • Post-Test Infrastructure: As pre-test wait times decrease, healthcare systems must prepare for increased demand for post-test counseling (cascade testing, segregation analysis).
• Future Directions: The authors call for further research into scalable educational tools for non-genetic clinicians and the development of curricula for cardiology fellows to better integrate genetic concepts into routine practice.

Conclusion: Mainstreaming cardiac genetic testing is a viable strategy to improve access and reduce wait times, but it requires structured educational interventions to ensure patients make truly informed choices. A hybrid approach that leverages the efficiency of cardiologists while retaining the expertise of genetic counselors for complex counseling needs offers the optimal balance.