Assessing the recovery after cardiac surgery: Development and validation of the Fuwai-CRS (Fuwai-Cardiac Recovery Scale)

This study developed and validated the Fuwai-Cardiac Recovery Scale (Fuwai-CRS), a concise 9-item tool designed to effectively assess patient-reported recovery outcomes following cardiac surgery.

The Gist

Imagine you just had a major heart surgery. The doctors tell you the operation was a success, your heart is fixed, and you're alive. But how do you feel? Are you in pain? Can you walk to the kitchen? Do you feel exhausted or thirsty?

For a long time, the medical world has been like a car mechanic who only checks if the engine starts (did the patient survive?) but never asks if the ride is smooth (how is the patient recovering?). This paper is about building a new, custom-made "dashboard" specifically for heart surgery patients to measure that ride.

Here is the story of how they built the Fuwai-CRS, explained simply:

1. The Problem: Using a Generic Map for a Special Journey

Before this study, doctors used "generic" recovery checklists. Think of these like a universal travel guide for all tourists. It works okay for a beach vacation or a city tour, but it doesn't tell you much about the specific challenges of climbing Mount Everest.

• The Issue: Heart surgery is unique. It involves a big cut in the chest, a machine that takes over your heart and lungs, and a very specific kind of physical toll. Generic guides missed the specific "Mount Everest" symptoms heart patients face, like extreme thirst or a specific type of weakness.
• The Goal: The researchers wanted to build a custom GPS just for heart surgery recovery.

2. The Construction: Listening to the Passengers

To build this new tool, the team at Fuwai Hospital (a top heart center in China) didn't just sit in an office and guess. They went out and talked to the people who actually lived through the journey.

• The Interview Phase (Cohort 1): They sat down with 31 patients, 5 doctors, and 4 nurses. They asked, "What was the hardest part?" and "What did you worry about?"
  • Analogy: Imagine asking a group of hikers, "What made the climb hardest?" Some said the steep rocks, others said the cold wind, and one said, "I was so thirsty I couldn't think."
• The Expert Panel (Delphi Method): They took all those complaints and suggestions to a panel of 15 experts (doctors, nurses, researchers). It was like a committee of architects reviewing a blueprint. They voted on which questions were truly important and which were just noise.
  • Result: They started with a draft list of 17 questions.

3. The Stress Test: Fitting the Pieces Together

Next, they gave this 17-question draft to 500 actual heart surgery patients (Cohort 2) to test it out. They wanted to see if the questions made sense and if they could actually measure recovery accurately.

• The Cleanup: Some questions were redundant (asking the same thing twice) or didn't apply to everyone.
  • The "Emotion" Filter: They initially included questions about sadness and anxiety. However, data showed that while some patients felt sad, most didn't feel it every single day right after surgery. So, they cut those questions to keep the tool focused on the physical recovery that happens to everyone.
  • The "Floor/Ceiling" Check: Imagine a thermometer that only reads "Freezing" or "Boiling" but never the middle temperatures. Some questions were like that—they were either always "0" (no problem) or always "10" (worst problem). The researchers removed these because they didn't help track the change in recovery.
• The Final Product: After all the cutting and testing, they were left with a sleek, 9-item scale.

4. What's on the Dashboard?

The final Fuwai-CRS asks patients to rate 9 specific things on a scale of 0 to 10 (0 being "I feel great," 10 being "This is the worst pain imaginable").

The 9 questions cover the "Big 9" of heart recovery:

1. Shortness of breath (Can I breathe?)
2. Poor appetite (Can I eat?)
3. Nausea/Vomiting (Is my stomach okay?)
4. Poor sleep (Did I rest?)
5. Pain (Does it hurt?)
6. Thirst (This is a big one! Heart surgery often involves fluid shifts that make patients incredibly thirsty, a symptom generic scales missed.)
7. Fatigue (Am I exhausted?)
8. Unable to manage personal care (Can I use the bathroom/wash myself?)
9. Poor mobility (Can I walk?)

5. Why This Matters

The researchers proved this new tool works like a charm:

• It's reliable: If you ask the same person twice, they give similar answers.
• It's valid: It matches up with other known good tests.
• It's sensitive: It can detect small improvements. If a patient goes from a "9" to a "7" on pain, this scale sees it.

The Bottom Line:
This paper is about giving heart surgery patients a voice. Instead of just saying, "You survived," doctors can now say, "We see you are thirsty and tired, let's fix that." It turns recovery from a vague concept into a clear, measurable journey, ensuring that the patient's experience is just as important as the surgery itself.

Technical Summary

1. Problem Statement

Despite advancements in surgical techniques that have reduced procedural mortality, cardiac surgery imposes significant physiological challenges (e.g., pain, sleep disorders, fatigue) that impact patient recovery. Current Patient-Reported Outcome Measures (PROMs) used to assess recovery are inadequate for this specific population:

• Generic tools (e.g., SF-36, EQ-5D) lack cardiac-specific nuances.
• General surgery scales (e.g., QoR-15) were developed primarily for general anesthesia populations and may not capture unique cardiac recovery challenges.
• Cardiovascular disease-specific tools (e.g., KCCQ) focus on chronic heart failure rather than the acute postoperative recovery trajectory.
• Gap: There is no widely accepted, cardiac surgery-specific PROM designed to capture the dynamic, heterogeneous, and rapid changes in recovery status immediately following surgery.

2. Methodology

The study followed FDA guidance for PROM development and validation, utilizing a two-cohort, mixed-methods prospective design conducted between May 2023 and December 2024 at Fuwai Hospital, China.

Cohort 1: Qualitative Development (Item Generation)

• Participants: 31 postoperative cardiac surgery patients (maximum variation sampling) and 9 medical staff (doctors/nurses with >5 years experience).
• Process:
  • Literature Review & Interviews: Generated an initial item pool covering 9 domains.
  • Delphi Consensus: A panel of 15 experts (clinicians, nurses, researchers) evaluated items using a 5-point Likert scale over two rounds. Items with average scores $\ge$ (Mean - SD) were retained.
  • Outcome: A 17-item draft scale (Fuwai-CRS) was created, using a 24-hour recall period and an 11-point numeric rating scale (0 = not present, 10 = as bad as you can imagine).

Cohort 2: Psychometric Validation (Item Finalization)

• Participants: 500 patients scheduled for elective cardiac surgery.
• Data Collection: Patients completed the draft scale at multiple time points (pre-op, Days 1–4, Weeks 2–3, Months 1 and 3) and the validated Chinese QoR-15 for comparison. A subset (n=21) underwent cognitive debriefing.
• Item Reduction Strategy: Three statistical methods were applied to eliminate redundant or non-informative items:
  1. Data Distribution Assessment: Eliminated items with >30% floor or ceiling effects.
  2. Hierarchical Cluster Analysis: Grouped similar items to remove redundancy.
  3. Exploratory Factor Analysis (EFA): Retained items with factor loadings >0.4.
• Validation Metrics:
  • Reliability: Internal consistency (Cronbach's $\alpha$) and test-retest reliability (Intraclass Correlation Coefficient, ICC).
  • Validity: Criterion validity (Pearson correlation with QoR-15) and known-group validity (comparing scores based on LVEF and hospital stay length).
  • Responsiveness: Measured via Cohen's effect size and Standardized Response Mean (SRM) comparing baseline vs. postoperative scores.

3. Key Contributions

• Development of Fuwai-CRS: The creation of the first cardiac surgery-specific PROM tailored to the unique recovery trajectory of these patients.
• Specific Domain Inclusion: Unlike generic scales, the final scale includes domains critical to cardiac recovery, specifically thirst (related to fluid management post-bypass) and fatigue (related to inflammatory response and cardiac function).
• Methodological Rigor: The study adhered strictly to FDA guidelines, employing a robust combination of qualitative input, Delphi consensus, and rigorous statistical item reduction (Cluster analysis + EFA).
• Efficiency: The final tool is concise (9 items), taking approximately one minute to complete, facilitating high follow-up rates in clinical settings.

4. Results

• Item Reduction: From the initial 17-item draft, 8 items were eliminated.
  • Eliminated due to Floor Effect (>30%): Emotional domains (worried/anxious, sad/depressed, uncomfortable/out of control) and severe pain. These were common but not ubiquitous in the acute phase.
  • Eliminated due to Ceiling Effect (>30%): Items regarding inability to work/usual activities and inability to manage personal care (patients were too impaired to report "no problem" or the scale didn't capture the nuance).
  • Eliminated via Clustering: "Exhaustion" was removed as it clustered with "Fatigue."
• Final Scale: The 9-item Fuwai-CRS includes: Shortness of breath, Poor appetite, Nausea/vomiting, Poor sleep, Pain, Thirst, Fatigue, Unable to manage personal toileting/hygiene, and Poor mobility.
• Psychometric Properties:
  • Reliability: Good internal consistency ($\alpha = 0.714$) and test-retest reliability (ICC = 0.795).
  • Validity: Strong correlation with the QoR-15 ($r = 0.875$). Known-group validity was confirmed, with significant score differences observed between patients with LVEF <45% vs. $\ge$45% and those with hospital stays $\ge$7 days vs. <7 days.
  • Responsiveness: Excellent responsiveness to change, with a Cohen's effect size of 4.66 and an SRM of 2.53.
• Feasibility: Cognitive debriefing showed 90.5% of patients found the tool easy to understand and complete.

5. Significance

• Clinical Utility: The Fuwai-CRS provides a standardized, rapid, and valid tool for clinicians to monitor postoperative recovery, identify specific symptom burdens (like thirst and fatigue), and tailor rehabilitation strategies.
• Research Impact: It fills a critical gap in cardiac surgery literature by offering a disease-specific metric, moving beyond generic quality-of-life measures. This allows for more precise comparisons in clinical trials and observational studies.
• Future Directions: While currently validated in a Chinese population, the study lays the groundwork for multi-lingual adaptation. The authors suggest future research could append specific subscales to the core Fuwai-CRS to address unique patient conditions (e.g., specific valve types or congenital defects).

Limitations: The study was single-center (Fuwai Hospital, China), limiting global generalizability. Future work requires cross-cultural validation and translation into other languages. Additionally, emotional domains were excluded from the core scale due to low prevalence in the acute phase, though they remain relevant for long-term recovery.