Exhibit 99.24 MBNA MASTER CREDIT CARD TRUST II SERIES 1997-B KEY PERFORMANCE FACTORS January 31, 1999 Expected B Maturity 3/15/12 Blended Coupon 5.2335% Excess Protection Level 3 Month Average 5.72% January, 1999 5.68% December, 1998 5.78% November, 1998 5.68% Cash Yield 18.21% Investor Charge Offs 4.95% Base Rate 7.58% Over 35 Day Delinquency 5.29% Seller's Interest 8.19% Total Payment Rate 14.12% Total Principal Balance $40,086,865,639.98 Investor Participation Amount $1,000,000,000.00 Seller Participation Amount $3,284,946,121.49