Exhibit 99.24 MBNA MASTER CREDIT CARD TRUST II SERIES 1997-B KEY PERFORMANCE FACTORS April 30, 1997 Expected B Maturity 3/15/12 Blended Coupon 5.7538% Excess Protection Level 3 Month Average 3.47% April, 1997 3.47% March, 1997 N/A February, 1997 N/A Cash Yield 16.70% Investor Charge Offs 4.31% Base Rate 8.92% Over 35 Day Delinquency 4.27% Seller's Interest 20.02% Total Payment Rate 12.21% Total Principal Balance $27,182,850,184.68 Investor Participation Amount $1,000,000,000.00 Seller Participation Amount $5,443,222,666.19 * For the purposes of calculating the Base Rate and Excess Protection Level, a Coupon of 6.92% (64/360) was used. The Base Rate was calculated using a 64 day monthly period, 2/27/97-4/30/97.